37 lines
1.3 KiB
C#
37 lines
1.3 KiB
C#
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using System;
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using System.Data.Common;
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using Marr.Data.QGen.Dialects;
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using System.Linq.Expressions;
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namespace Marr.Data.QGen
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{
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/// <summary>
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/// This class overrides the WhereBuilder which utilizes the ExpressionVisitor base class,
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/// and it is responsible for translating the lambda expression into a "JOIN ON" clause.
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/// It populates the protected string builder, which outputs the "JOIN ON" clause when the ToString method is called.
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/// </summary>
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/// <typeparam name="T">The entity that is on the left side of the join.</typeparam>
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/// <typeparam name="T2">The entity that is on the right side of the join.</typeparam>
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public class JoinBuilder<T, T2> : WhereBuilder<T>
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{
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public JoinBuilder(DbCommand command, Dialect dialect, Expression<Func<T, T2, bool>> filter, TableCollection tables)
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: base(command, dialect, filter.Body, tables, false, true)
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{ }
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protected override string PrefixText
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{
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get
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{
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return "ON";
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}
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}
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protected override Expression VisitMemberAccess(MemberExpression expression)
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{
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string fqColumn = GetFullyQualifiedColumnName(expression.Member, expression.Expression.Type);
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_sb.Append(fqColumn);
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return expression;
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}
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}
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}
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