File: System\Data\OleDb\OleDbMetaDataFactory.cs
Project: ndp\fx\src\data\System.Data.csproj (System.Data)
//------------------------------------------------------------------------------
// <copyright file="OleDbMetaDataFactory.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
//
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Mugunm</owner>
//
//------------------------------------------------------------------------------
 
namespace System.Data.OleDb{
 
    using System;
    using System.Data;
    using System.IO;
    using System.Collections;
    using System.Data.ProviderBase;
    using System.Data.Common;
    using System.Diagnostics;
    using System.Globalization;
    using System.Text;
    using System.Xml;
    using System.Xml.Schema;
 
    internal sealed class OleDbMetaDataFactory : DbMetaDataFactory{ // V1.2.3300
 
        private struct SchemaRowsetName {
            internal SchemaRowsetName(string schemaName, Guid schemaRowset) {
                _schemaName = schemaName;
                _schemaRowset = schemaRowset;
            }
            internal readonly string  _schemaName;
            internal readonly Guid    _schemaRowset;
        }
 
 
 
        private const string _collectionName = "CollectionName";
        private const string _populationMechanism = "PopulationMechanism";
        private const string _prepareCollection = "PrepareCollection";
 
        private readonly SchemaRowsetName[] _schemaMapping;
 
        internal OleDbMetaDataFactory(Stream XMLStream,
                                    string serverVersion,
                                    string serverVersionNormalized,
                                    SchemaSupport[] schemaSupport):
            base(XMLStream, serverVersion, serverVersionNormalized) {
 
            // set up the colletion mane schema rowset guid mapping
           _schemaMapping = new SchemaRowsetName[] {
 
                 new SchemaRowsetName(DbMetaDataCollectionNames.DataTypes,OleDbSchemaGuid.Provider_Types),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Catalogs,OleDbSchemaGuid.Catalogs),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Collations,OleDbSchemaGuid.Collations),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Columns,OleDbSchemaGuid.Columns),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Indexes,OleDbSchemaGuid.Indexes),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Procedures,OleDbSchemaGuid.Procedures),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.ProcedureColumns,OleDbSchemaGuid.Procedure_Columns),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.ProcedureParameters,OleDbSchemaGuid.Procedure_Parameters),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Tables,OleDbSchemaGuid.Tables),
                 new SchemaRowsetName(OleDbMetaDataCollectionNames.Views,OleDbSchemaGuid.Views)};
 
            // verify the existance of the table in the data set
            DataTable metaDataCollectionsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.MetaDataCollections];
            if (metaDataCollectionsTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.MetaDataCollections);
            }
 
            // copy the table filtering out any rows that don't apply to the current version of the provider
            metaDataCollectionsTable = CloneAndFilterCollection(DbMetaDataCollectionNames.MetaDataCollections, null);
 
            // verify the existance of the table in the data set
            DataTable restrictionsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.Restrictions];
            if (restrictionsTable != null){
                // copy the table filtering out any rows that don't apply to the current version of the provider
                restrictionsTable= CloneAndFilterCollection(DbMetaDataCollectionNames.Restrictions, null);
            }
 
            // need to filter out any of the collections where
            // 1) it is populated using prepare collection
            // 2) it is in the collection to schema rowset mapping above
            // 3) the provider does not support the necessary schema rowset
 
 
 
            DataColumn populationMechanism = metaDataCollectionsTable.Columns[_populationMechanism];
            if ((null == populationMechanism) || (typeof(System.String) != populationMechanism.DataType)) {
                throw ADP.InvalidXmlMissingColumn(DbMetaDataCollectionNames.MetaDataCollections,_populationMechanism);
            }
            DataColumn collectionName = metaDataCollectionsTable.Columns[_collectionName];
            if ((null == collectionName) || (typeof(System.String) != collectionName.DataType)) {
                 throw ADP.InvalidXmlMissingColumn(DbMetaDataCollectionNames.MetaDataCollections,_collectionName);
            }
            DataColumn restrictionCollectionName = null;
            if (restrictionsTable != null){
                restrictionCollectionName = restrictionsTable.Columns[_collectionName];
                if ((null == restrictionCollectionName) || (typeof(System.String) != restrictionCollectionName.DataType)) {
                    throw ADP.InvalidXmlMissingColumn(DbMetaDataCollectionNames.Restrictions,_collectionName);
                }
            }
 
            foreach (DataRow collection in metaDataCollectionsTable.Rows){
 
                string populationMechanismValue = collection[populationMechanism] as string;
                if (ADP.IsEmpty(populationMechanismValue )) {
                    throw ADP.InvalidXmlInvalidValue(DbMetaDataCollectionNames.MetaDataCollections,_populationMechanism);
                }
                string collectionNameValue = collection[collectionName] as string;
                if (ADP.IsEmpty(collectionNameValue)) {
                    throw ADP.InvalidXmlInvalidValue(DbMetaDataCollectionNames.MetaDataCollections,_collectionName);
                }
 
                if (populationMechanismValue == _prepareCollection) {
                    // is the collection in the mapping
                    int mapping = -1;
                    for (int i = 0; i < _schemaMapping.Length; i++){
                        if (_schemaMapping[i]._schemaName == collectionNameValue){
                            mapping = i;
                            break;
                        }
                    }
                    // no go on to the next collection
                    if (mapping == -1) {
                        continue;
                    }
 
                    // does the provider support the necessary schema rowset
                    bool isSchemaRowsetSupported = false;
                    if (schemaSupport != null){
                        for (int i = 0; i < schemaSupport.Length; i++){
                            if (_schemaMapping[mapping]._schemaRowset == schemaSupport[i]._schemaRowset){
                                isSchemaRowsetSupported = true;
                                break;
                            }
                        }
                    }
                    // if not delete the row from the table
                    if (isSchemaRowsetSupported == false){
                        // but first delete any related restrictions
                        if (restrictionsTable != null) {
                            foreach (DataRow restriction in restrictionsTable.Rows) {
                                string restrictionCollectionNameValue = restriction[restrictionCollectionName] as string;
                                if (ADP.IsEmpty(restrictionCollectionNameValue)) {
                                    throw ADP.InvalidXmlInvalidValue(DbMetaDataCollectionNames.Restrictions,_collectionName);
                                }
                                if (collectionNameValue == restrictionCollectionNameValue) {
                                    restriction.Delete();
                                }
                            }
                            restrictionsTable.AcceptChanges();
                        }
                        collection.Delete();
                    }
 
                }
            }
 
            // replace the original table with the updated one
            metaDataCollectionsTable.AcceptChanges();
            CollectionDataSet.Tables.Remove(CollectionDataSet.Tables[DbMetaDataCollectionNames.MetaDataCollections]);
            CollectionDataSet.Tables.Add(metaDataCollectionsTable);
 
            if (restrictionsTable != null) {
                CollectionDataSet.Tables.Remove(CollectionDataSet.Tables[DbMetaDataCollectionNames.Restrictions]);
                CollectionDataSet.Tables.Add(restrictionsTable);
            }
 
        }
 
        private String BuildRegularExpression(string invalidChars, string invalidStartingChars){
 
            StringBuilder regularExpression = new StringBuilder("[^");
            ADP.EscapeSpecialCharacters(invalidStartingChars,regularExpression);
            regularExpression.Append("][^");
            ADP.EscapeSpecialCharacters(invalidChars,regularExpression);
            regularExpression.Append("]*");
 
            return regularExpression.ToString();
        }
 
 
 
        private DataTable GetDataSourceInformationTable(OleDbConnection connection, OleDbConnectionInternal internalConnection){
 
            // verify that the data source information table is in the data set
            DataTable dataSourceInformationTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.DataSourceInformation];
            if (dataSourceInformationTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.DataSourceInformation);
            }
 
            // copy the table filtering out any rows that don't apply to tho current version of the prrovider
            dataSourceInformationTable = CloneAndFilterCollection(DbMetaDataCollectionNames.DataSourceInformation, null);
 
            // after filtering there better be just one row
            if (dataSourceInformationTable.Rows.Count != 1){
                throw ADP.IncorrectNumberOfDataSourceInformationRows();
            }
            DataRow dataSourceInformation = dataSourceInformationTable.Rows[0];
 
            // update the identifier separator
            string catalogSeparatorPattern = internalConnection.GetLiteralInfo(ODB.DBLITERAL_CATALOG_SEPARATOR);
            string schemaSeparatorPattern = internalConnection.GetLiteralInfo(ODB.DBLITERAL_SCHEMA_SEPARATOR);
 
            if (catalogSeparatorPattern != null) {
                StringBuilder compositeSeparatorPattern = new StringBuilder();
                StringBuilder patternEscaped = new StringBuilder();
                ADP.EscapeSpecialCharacters(catalogSeparatorPattern,patternEscaped);
                compositeSeparatorPattern.Append(patternEscaped.ToString());
                if ((schemaSeparatorPattern != null) && (schemaSeparatorPattern != catalogSeparatorPattern)) {
                    compositeSeparatorPattern.Append("|");
                    patternEscaped.Length = 0;
                    ADP.EscapeSpecialCharacters(schemaSeparatorPattern,patternEscaped);
                    compositeSeparatorPattern.Append(patternEscaped.ToString());
                }
                    dataSourceInformation[DbMetaDataColumnNames.CompositeIdentifierSeparatorPattern] = compositeSeparatorPattern.ToString();
            }
            else if (schemaSeparatorPattern != null){
                StringBuilder patternEscaped = new StringBuilder();
                ADP.EscapeSpecialCharacters(schemaSeparatorPattern, patternEscaped);
                dataSourceInformation[DbMetaDataColumnNames.CompositeIdentifierSeparatorPattern] = patternEscaped.ToString();;
            }
 
            // update the DataSourceProductName
            object property;
            property = connection.GetDataSourcePropertyValue(OleDbPropertySetGuid.DataSourceInfo,ODB.DBPROP_DBMSNAME);
            if (property != null) {
                dataSourceInformation[DbMetaDataColumnNames.DataSourceProductName] = (string) property;
            }
 
            // update the server version strings
            dataSourceInformation[DbMetaDataColumnNames.DataSourceProductVersion] = ServerVersion;
            dataSourceInformation[DbMetaDataColumnNames.DataSourceProductVersionNormalized] = ServerVersionNormalized;
 
 
                // values that are the same for all OLE DB Providers. See SQLBU 308529
                dataSourceInformation[DbMetaDataColumnNames.ParameterMarkerFormat] =  "?";
                dataSourceInformation[DbMetaDataColumnNames.ParameterMarkerPattern] =  "\\?";
                dataSourceInformation[DbMetaDataColumnNames.ParameterNameMaxLength] = 0;
 
 
            property = connection.GetDataSourcePropertyValue(OleDbPropertySetGuid.DataSourceInfo,ODB.DBPROP_GROUPBY);
            GroupByBehavior groupByBehavior = GroupByBehavior.Unknown;
            if (property != null) {
                switch ((int)property) {
 
                    case ODB.DBPROPVAL_GB_CONTAINS_SELECT:
                        groupByBehavior = GroupByBehavior.MustContainAll;
                        break;
 
                    case ODB.DBPROPVAL_GB_EQUALS_SELECT:
                        groupByBehavior = GroupByBehavior.ExactMatch;
                        break;
 
                    case ODB.DBPROPVAL_GB_NO_RELATION:
                        groupByBehavior = GroupByBehavior.Unrelated;
                        break;
 
                    case ODB.DBPROPVAL_GB_NOT_SUPPORTED:
                        groupByBehavior = GroupByBehavior.NotSupported;
                        break;
                }
            }
            dataSourceInformation[DbMetaDataColumnNames.GroupByBehavior] = groupByBehavior;
 
            SetIdentifierCase(DbMetaDataColumnNames.IdentifierCase,ODB.DBPROP_IDENTIFIERCASE,dataSourceInformation, connection);
            SetIdentifierCase(DbMetaDataColumnNames.QuotedIdentifierCase,ODB.DBPROP_QUOTEDIDENTIFIERCASE,dataSourceInformation, connection);
 
            property = connection.GetDataSourcePropertyValue(OleDbPropertySetGuid.DataSourceInfo,ODB.DBPROP_ORDERBYCOLUNSINSELECT);
            if (property != null) {
                dataSourceInformation[DbMetaDataColumnNames.OrderByColumnsInSelect] = (bool) property;
            }
 
            DataTable infoLiterals = internalConnection.BuildInfoLiterals();
            if (infoLiterals != null){
                DataRow[] tableNameRow = infoLiterals.Select("Literal = " + ODB.DBLITERAL_TABLE_NAME.ToString(CultureInfo.InvariantCulture));
                if (tableNameRow != null) {
                    object invalidCharsObject = tableNameRow[0]["InvalidChars"];
                    if (invalidCharsObject.GetType() == typeof(string)) {
                        string invalidChars = (string)invalidCharsObject;
                        object invalidStartingCharsObject = tableNameRow[0]["InvalidStartingChars"];
                        string invalidStartingChars;
                        if (invalidStartingCharsObject.GetType() == typeof(string)) {
                            invalidStartingChars = (string)invalidStartingCharsObject;
                        }
                        else {
                            invalidStartingChars = invalidChars;
                        }
                        dataSourceInformation[DbMetaDataColumnNames.IdentifierPattern] =
                                                    BuildRegularExpression(invalidChars,invalidStartingChars);
                    }
                }
            }
 
            // build the QuotedIdentifierPattern using the quote prefix and suffix from the provider and
            // assuming that the quote suffix is escaped via repetion (i.e " becomes "")
            string quotePrefix;
            string quoteSuffix;
            connection.GetLiteralQuotes(ADP.GetSchema, out quotePrefix, out quoteSuffix);
 
            if (quotePrefix != null){
 
                // if the quote suffix is null assume that it is the same as the prefix (See OLEDB spec
                // IDBInfo::GetLiteralInfo DBLITERAL_QUOTE_SUFFIX.)
                if (quoteSuffix == null) {
                    quoteSuffix = quotePrefix;
                }
 
                // only know how to build the parttern if the suffix is 1 character
                // in all other cases just leave the field null
                if (quoteSuffix.Length == 1) {
                    StringBuilder scratchStringBuilder = new StringBuilder();
                    ADP.EscapeSpecialCharacters(quoteSuffix,scratchStringBuilder );
                    string escapedQuoteSuffixString = scratchStringBuilder.ToString();
                    scratchStringBuilder.Length = 0;
 
                    ADP.EscapeSpecialCharacters(quotePrefix, scratchStringBuilder);
                    scratchStringBuilder.Append("(([^");
                    scratchStringBuilder.Append(escapedQuoteSuffixString);
                    scratchStringBuilder.Append("]|");
                    scratchStringBuilder.Append(escapedQuoteSuffixString);
                    scratchStringBuilder.Append(escapedQuoteSuffixString);
                    scratchStringBuilder.Append(")*)");
                    scratchStringBuilder.Append(escapedQuoteSuffixString);
                    dataSourceInformation[DbMetaDataColumnNames.QuotedIdentifierPattern] = scratchStringBuilder.ToString();
                }
            }
 
            dataSourceInformationTable.AcceptChanges();
 
            return dataSourceInformationTable;
        }
 
        private DataTable GetDataTypesTable(OleDbConnection connection){
 
            // verify the existance of the table in the data set
            DataTable dataTypesTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.DataTypes];
            if (dataTypesTable == null){
                throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.DataTypes);
            }
 
            // copy the table filtering out any rows that don't apply to tho current version of the prrovider
            dataTypesTable = CloneAndFilterCollection(DbMetaDataCollectionNames.DataTypes, null);
 
            DataTable providerTypesTable = connection.GetOleDbSchemaTable(OleDbSchemaGuid.Provider_Types,null);
 
 
            DataColumn[] targetColumns = new DataColumn[] {
                dataTypesTable.Columns[DbMetaDataColumnNames.TypeName],
                dataTypesTable.Columns[DbMetaDataColumnNames.ColumnSize],
                dataTypesTable.Columns[DbMetaDataColumnNames.CreateParameters],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsAutoIncrementable],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsCaseSensitive],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsFixedLength],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsFixedPrecisionScale],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsLong],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsNullable],
                dataTypesTable.Columns[DbMetaDataColumnNames.IsUnsigned],
                dataTypesTable.Columns[DbMetaDataColumnNames.MaximumScale],
                dataTypesTable.Columns[DbMetaDataColumnNames.MinimumScale],
                dataTypesTable.Columns[DbMetaDataColumnNames.LiteralPrefix],
                dataTypesTable.Columns[DbMetaDataColumnNames.LiteralSuffix],
                dataTypesTable.Columns[OleDbMetaDataColumnNames.NativeDataType]};
 
            DataColumn[] sourceColumns = new DataColumn[] {
                providerTypesTable.Columns["TYPE_NAME"],
                providerTypesTable.Columns["COLUMN_SIZE"],
                providerTypesTable.Columns["CREATE_PARAMS"],
                providerTypesTable.Columns["AUTO_UNIQUE_VALUE"],
                providerTypesTable.Columns["CASE_SENSITIVE"],
                providerTypesTable.Columns["IS_FIXEDLENGTH"],
                providerTypesTable.Columns["FIXED_PREC_SCALE"],
                providerTypesTable.Columns["IS_LONG"],
                providerTypesTable.Columns["IS_NULLABLE"],
                providerTypesTable.Columns["UNSIGNED_ATTRIBUTE"],
                providerTypesTable.Columns["MAXIMUM_SCALE"],
                providerTypesTable.Columns["MINIMUM_SCALE"],
                providerTypesTable.Columns["LITERAL_PREFIX"],
                providerTypesTable.Columns["LITERAL_SUFFIX"],
                providerTypesTable.Columns["DATA_TYPE"]};
 
            Debug.Assert(sourceColumns.Length == targetColumns.Length);
 
            DataColumn isSearchable = dataTypesTable.Columns[DbMetaDataColumnNames.IsSearchable];
            DataColumn isSearchableWithLike = dataTypesTable.Columns[DbMetaDataColumnNames.IsSearchableWithLike];
            DataColumn providerDbType = dataTypesTable.Columns[DbMetaDataColumnNames.ProviderDbType];
            DataColumn clrType = dataTypesTable.Columns[DbMetaDataColumnNames.DataType];
            DataColumn isLong = dataTypesTable.Columns[DbMetaDataColumnNames.IsLong];
            DataColumn isFixed = dataTypesTable.Columns[DbMetaDataColumnNames.IsFixedLength];
            DataColumn sourceOleDbType = providerTypesTable.Columns["DATA_TYPE"];
 
            DataColumn searchable = providerTypesTable.Columns["SEARCHABLE"];
 
 
            foreach (DataRow sourceRow in providerTypesTable.Rows) {
                DataRow newRow = dataTypesTable.NewRow();
                for (int i = 0; i < sourceColumns.Length; i++) {
                    if ((sourceColumns[i] != null) && (targetColumns[i] != null)){
                        newRow[targetColumns[i]] = sourceRow[sourceColumns[i]];
                    }
                }
 
 
                short nativeDataType = (short) Convert.ChangeType(sourceRow[sourceOleDbType],typeof(short), CultureInfo.InvariantCulture);
                NativeDBType nativeType = NativeDBType.FromDBType(nativeDataType,(bool)newRow[isLong], (bool)newRow[isFixed]);
 
                newRow[clrType] = nativeType.dataType.FullName;
                newRow[providerDbType] = nativeType.enumOleDbType;
 
                // searchable has to be special cased becasue it is not an eaxct mapping
                if ((isSearchable != null) && (isSearchableWithLike != null) && (searchable != null)) {
 
                    newRow[isSearchable] = DBNull.Value;
                    newRow[isSearchableWithLike] = DBNull.Value;
                    if ( DBNull.Value != sourceRow[searchable]){
 
                        Int64 searchableValue = (Int64)(sourceRow[searchable]);
                        switch (searchableValue){
 
                            case ODB.DB_UNSEARCHABLE:
                                newRow[isSearchable] = false;
                                newRow[isSearchableWithLike] = false;
                                break;
 
                            case ODB.DB_LIKE_ONLY:
                                newRow[isSearchable] = false;
                                newRow[isSearchableWithLike] = true;
                                break;
 
                            case ODB.DB_ALL_EXCEPT_LIKE:
                                newRow[isSearchable] = true;
                                newRow[isSearchableWithLike] = false;
                                break;
 
                            case ODB.DB_SEARCHABLE:
                                newRow[isSearchable] = true;
                                newRow[isSearchableWithLike] = true;
                                break;
                        }
                    }
                }
 
                dataTypesTable.Rows.Add(newRow);
            }
 
 
            dataTypesTable.AcceptChanges();
            
            return  dataTypesTable;
 
        }
 
 
        private DataTable GetReservedWordsTable(OleDbConnectionInternal internalConnection){
 
            // verify the existance of the table in the data set
            DataTable reservedWordsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.ReservedWords];
            if (null == reservedWordsTable){
                    throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.ReservedWords);
            }
 
            // copy the table filtering out any rows that don't apply to tho current version of the prrovider
            reservedWordsTable = CloneAndFilterCollection(DbMetaDataCollectionNames.ReservedWords, null);
 
            DataColumn reservedWordColumn = reservedWordsTable.Columns[DbMetaDataColumnNames.ReservedWord];
            if (null == reservedWordColumn){
                    throw ADP.UnableToBuildCollection(DbMetaDataCollectionNames.ReservedWords);
            }
 
            if (!internalConnection.AddInfoKeywordsToTable(reservedWordsTable, reservedWordColumn)){
                    throw ODB.IDBInfoNotSupported();
            }
 
            return  reservedWordsTable;
        }
 
 
 
        protected override DataTable PrepareCollection(String collectionName, String[] restrictions, DbConnection connection){
 
            OleDbConnection oleDbConnection = (OleDbConnection) connection;
            OleDbConnectionInternal oleDbInternalConnection = (OleDbConnectionInternal) (oleDbConnection.InnerConnection);
            DataTable resultTable = null;
            if (collectionName == DbMetaDataCollectionNames.DataSourceInformation){
                if (ADP.IsEmptyArray(restrictions) == false){
                    throw ADP.TooManyRestrictions(DbMetaDataCollectionNames.DataSourceInformation);
                }
                resultTable = GetDataSourceInformationTable(oleDbConnection, oleDbInternalConnection);
            }
            else if (collectionName == DbMetaDataCollectionNames.DataTypes){
                if (ADP.IsEmptyArray(restrictions) == false){
                    throw ADP.TooManyRestrictions(DbMetaDataCollectionNames.DataTypes);
                }
                resultTable = GetDataTypesTable(oleDbConnection);
            }
            else if (collectionName == DbMetaDataCollectionNames.ReservedWords){
                if (ADP.IsEmptyArray(restrictions) == false){
                    throw ADP.TooManyRestrictions(DbMetaDataCollectionNames.ReservedWords);
                }
                resultTable = GetReservedWordsTable(oleDbInternalConnection);
            }
            else {
                for (int i=0; i < _schemaMapping.Length; i++){
                    if (_schemaMapping[i]._schemaName== collectionName) {
 
                        // need to special case the oledb schema rowset restrictions on columns that are not
                        // string tpyes
                        object[] mungedRestrictions = restrictions;;
                        if (restrictions != null){
                            //verify that there are not too many restrictions
                            DataTable   metaDataCollectionsTable = CollectionDataSet.Tables[DbMetaDataCollectionNames.MetaDataCollections];
                            int numberOfSupportedRestictions = -1;
                            // prepare colletion is called with the exact collection name so
                            // we can do an exact string comparision here
                            foreach (DataRow row in metaDataCollectionsTable.Rows){
                                string candidateCollectionName = ((string)row[DbMetaDataColumnNames.CollectionName,DataRowVersion.Current]);
 
                                if (collectionName == candidateCollectionName) {
                                    numberOfSupportedRestictions = (int)row[DbMetaDataColumnNames.NumberOfRestrictions];
                                    if (numberOfSupportedRestictions < restrictions.Length){
                                        throw ADP.TooManyRestrictions(collectionName);
                                    }
                                    break;
                                }
                            }
 
                            Debug.Assert(numberOfSupportedRestictions != -1, "PrepareCollection was called for an collection that is not supported.");
 
                            // the 4th restrictionon the indexes schema rowset(type) is an I2 - enum
                            const int indexRestrictionTypeSlot = 3;
 
                            if ((collectionName == OleDbMetaDataCollectionNames.Indexes) &&
                                (restrictions.Length >= indexRestrictionTypeSlot+1) &&
                                (restrictions[indexRestrictionTypeSlot] != null)){
 
                                mungedRestrictions = new object[restrictions.Length];
                                for (int j = 0; j <restrictions.Length; j++){
                                    mungedRestrictions[j] = restrictions[j];
                                }
                                
                                UInt16 indexTypeValue;
                                                                
                                if ((restrictions[indexRestrictionTypeSlot] == "DBPROPVAL_IT_BTREE") ||
                                    (restrictions[indexRestrictionTypeSlot] == "1")){
                                    indexTypeValue = 1;
                                }
                                else if ((restrictions[indexRestrictionTypeSlot] == "DBPROPVAL_IT_HASH") ||
                                    (restrictions[indexRestrictionTypeSlot] == "2")){
                                    indexTypeValue = 2;
                                }
                                else if ((restrictions[indexRestrictionTypeSlot] == "DBPROPVAL_IT_CONTENT") ||
                                    (restrictions[indexRestrictionTypeSlot] == "3")){
                                    indexTypeValue = 3;
                                }
                                else if ((restrictions[indexRestrictionTypeSlot] == "DBPROPVAL_IT_OTHER") ||
                                    (restrictions[indexRestrictionTypeSlot] == "4")){
                                    indexTypeValue = 4;
                                }
                                else {
                                    throw ADP.InvalidRestrictionValue(collectionName,"TYPE",restrictions[indexRestrictionTypeSlot]);
                                }
                                
                                mungedRestrictions[indexRestrictionTypeSlot] = indexTypeValue;
 
                            }
 
                            // the 4th restrictionon the procedures schema rowset(type) is an I2 - enum
                            const int procedureRestrictionTypeSlot = 3;
 
                            if ((collectionName == OleDbMetaDataCollectionNames.Procedures) &&
                                (restrictions.Length >= procedureRestrictionTypeSlot+1) &&
                                (restrictions[procedureRestrictionTypeSlot] != null)){
 
                                mungedRestrictions = new object[restrictions.Length];
                                for (int j = 0; j <restrictions.Length; j++){
                                    mungedRestrictions[j] = restrictions[j];
                                }
 
                                Int16 procedureTypeValue;
                                
                                if ((restrictions[procedureRestrictionTypeSlot] == "DB_PT_UNKNOWN") ||
                                    (restrictions[procedureRestrictionTypeSlot] == "1")){
                                    procedureTypeValue = 1;
                                }
                                else if ((restrictions[procedureRestrictionTypeSlot] == "DB_PT_PROCEDURE")||
                                    (restrictions[procedureRestrictionTypeSlot] == "2")){
                                    procedureTypeValue = 2;
                                }
                                else if ((restrictions[procedureRestrictionTypeSlot] == "DB_PT_FUNCTION")||
                                    (restrictions[procedureRestrictionTypeSlot] == "3")){
                                    procedureTypeValue = 3;
                                }
                                else {
                                    throw ADP.InvalidRestrictionValue(collectionName,"PROCEDURE_TYPE",restrictions[procedureRestrictionTypeSlot]);
                                }
 
                                mungedRestrictions[procedureRestrictionTypeSlot] = procedureTypeValue;
 
                            }
                        }
 
                        resultTable = oleDbConnection.GetOleDbSchemaTable((System.Guid)_schemaMapping[i]._schemaRowset,mungedRestrictions);
                        break;
                    }
                }
            }
 
            if (resultTable == null){
               throw ADP.UnableToBuildCollection(collectionName);
            }
 
            return resultTable;
        }
 
        private void SetIdentifierCase(string columnName, int propertyID, DataRow row, OleDbConnection connection) {
 
            object property = connection.GetDataSourcePropertyValue(OleDbPropertySetGuid.DataSourceInfo,propertyID);
            IdentifierCase identifierCase = IdentifierCase.Unknown;
            if (property != null) {
                int propertyValue = (int)property;
                switch (propertyValue) {
                case ODB.DBPROPVAL_IC_UPPER:
                case ODB.DBPROPVAL_IC_LOWER:
                case ODB.DBPROPVAL_IC_MIXED:
                    identifierCase = IdentifierCase.Insensitive;
                    break;
 
                case ODB.DBPROPVAL_IC_SENSITIVE:
                    identifierCase = IdentifierCase.Sensitive;
                    break;
                }
            }
            row[columnName] = identifierCase;
 
        }
 
    }
}