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//------------------------------------------------------------------------------
// <copyright file="NameNode.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
// <owner current="true" primary="true">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
// <owner current="false" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------
namespace System.Data {
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
internal sealed class NameNode : ExpressionNode {
internal char open = '\0';
internal char close = '\0';
internal string name;
internal bool found;
internal bool type = false;
internal DataColumn column;
internal NameNode(DataTable table, char[] text, int start, int pos) : base(table) {
this.name = ParseName(text, start, pos);
}
internal NameNode(DataTable table, string name) : base(table) {
this.name = name;
}
internal override bool IsSqlColumn{
get{
return column.IsSqlType;
}
}
internal override void Bind(DataTable table, List<DataColumn> list) {
BindTable(table);
if (table == null)
throw ExprException.UnboundName(name);
try {
this.column = table.Columns[name];
}
catch (Exception e) {
found = false;
//
if (!Common.ADP.IsCatchableExceptionType(e)) {
throw;
}
throw ExprException.UnboundName(name);
}
if (column == null)
throw ExprException.UnboundName(name);
name = column.ColumnName;
found = true;
// add column to the dependency list, do not add duplicate columns
Debug.Assert(column != null, "Failed to bind column " + name);
int i;
for (i = 0; i < list.Count; i++) {
// walk the list, check if the current column already on the list
DataColumn dataColumn = list[i];
if (column == dataColumn) {
break;
}
}
if (i >= list.Count) {
list.Add(column);
}
}
internal override object Eval() {
// can not eval column without ROW value;
throw ExprException.EvalNoContext();
}
internal override object Eval(DataRow row, DataRowVersion version) {
if (!found) {
throw ExprException.UnboundName(name);
}
if (row == null) {
if(IsTableConstant()) // this column is TableConstant Aggregate Function
return column.DataExpression.Evaluate();
else {
throw ExprException.UnboundName(name);
}
}
return column[row.GetRecordFromVersion(version)];
}
internal override object Eval(int[] records) {
throw ExprException.ComputeNotAggregate(this.ToString());
}
internal override bool IsConstant() {
return false;
}
internal override bool IsTableConstant() {
if (column != null && column.Computed) {
return this.column.DataExpression.IsTableAggregate();
}
return false;
}
internal override bool HasLocalAggregate() {
if (column != null && column.Computed) {
return this.column.DataExpression.HasLocalAggregate();
}
return false;
}
internal override bool HasRemoteAggregate() {
if (column != null && column.Computed) {
return this.column.DataExpression.HasRemoteAggregate();
}
return false;
}
internal override bool DependsOn(DataColumn column) {
if (this.column == column)
return true;
if (this.column.Computed) {
return this.column.DataExpression.DependsOn(column);
}
return false;
}
internal override ExpressionNode Optimize() {
return this;
}
/// <devdoc>
/// Parses given name and checks it validity
/// </devdoc>
internal static string ParseName(char[] text, int start, int pos) {
char esc = '\0';
string charsToEscape = "";
int saveStart = start;
int savePos = pos;
if (text[start] == '`') {
Debug.Assert(text[checked((int)pos-1)] == '`', "Invalid identifyer bracketing, pos = " + pos.ToString(CultureInfo.InvariantCulture) + ", end = " + text[checked((int)pos-1)].ToString(CultureInfo.InvariantCulture));
start = checked((int)start+1);
pos = checked((int)pos-1);
esc = '\\';
charsToEscape = "`";
}
else if (text[start] == '[') {
Debug.Assert(text[checked((int)pos-1)] == ']', "Invalid identifyer bracketing of name " + new string(text, start, pos-start) + " pos = " + pos.ToString(CultureInfo.InvariantCulture) + ", end = " + text[checked((int)pos-1)].ToString(CultureInfo.InvariantCulture));
start = checked((int)start+1);
pos = checked((int)pos-1);
esc = '\\';
charsToEscape = "]\\";
}
if (esc != '\0') {
// scan the name in search for the ESC
int posEcho = start;
for (int i = start; i < pos; i++) {
if (text[i] == esc) {
if (i+1 < pos && charsToEscape.IndexOf(text[i+1]) >= 0) {
i++;
}
}
text[posEcho] = text[i];
posEcho++;
}
pos = posEcho;
}
if (pos == start)
throw ExprException.InvalidName(new string(text, saveStart, savePos - saveStart));
return new string(text, start, pos - start);
}
}
}
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