private void BuildMergeSourceEnumerable(SqlMergeStatement merge)
{
var rows = merge.Source.SourceEnumerable !.Rows !;
if (rows.Count > 0)
{
StringBuilder.Append("(");
if (MergeSupportsSourceDirectValues)
{
BuildValues(merge.Source.SourceEnumerable, rows);
}
else
{
BuildValuesAsSelectsUnion(merge.Source.SourceFields, merge.Source.SourceEnumerable, rows);
}
StringBuilder.Append(")");
}
else if (MergeEmptySourceSupported)
{
BuildMergeEmptySource(merge);
}
else
{
throw new LinqToDBException($"{Name} doesn't support merge with empty source");
}
BuildMergeAsSourceClause(merge.Source);
}
private void BuildMergeSourceEnumerable(SqlMergeStatement merge)
{
merge = ConvertElement(merge);
var rows = merge.Source.SourceEnumerable !.BuildRows(OptimizationContext.Context);
if (rows.Count > 0)
{
StringBuilder.Append('(');
if (IsValuesSyntaxSupported)
{
BuildValues(merge.Source.SourceEnumerable, rows);
}
else
{
BuildValuesAsSelectsUnion(merge.Source.SourceFields, merge.Source.SourceEnumerable, rows);
}
StringBuilder.Append(')');
}
else if (IsEmptyValuesSourceSupported)
{
BuildMergeEmptySource(merge);
}
else
{
throw new LinqToDBException($"{Name} doesn't support merge with empty source");
}
BuildMergeAsSourceClause(merge.Source);
}
protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
{
// MergeInto<TTarget, TSource>(IQueryable<TSource> source, ITable<TTarget> target, string hint)
var sourceContext = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0], new SelectQuery()));
var target = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[1])
{
AssociationsAsSubQueries = true
});
if (target is not TableBuilder.TableContext tableContext ||
!tableContext.SelectQuery.IsSimple)
{
throw new NotImplementedException("Currently, only CTEs are supported as the target of a merge. You can fix by calling .AsCte() on the parameter before passing into .MergeInto().");
}
var targetTable = tableContext.SqlTable;
var merge = new SqlMergeStatement(targetTable);
if (methodCall.Arguments.Count == 3)
{
merge.Hint = (string?)methodCall.Arguments[2].EvaluateExpression();
}
target.SetAlias(merge.Target.Alias !);
target.Statement = merge;
var source = new TableLikeQueryContext(sourceContext);
return(new MergeContext(merge, target, source));
}
protected virtual void BuildMergeOn(SqlMergeStatement mergeStatement)
{
StringBuilder.Append("ON (");
BuildSearchCondition(Precedence.Unknown, mergeStatement.On, wrapCondition: true);
StringBuilder.AppendLine(")");
}
protected override void BuildMergeTerminator(SqlMergeStatement merge)
{
// for identity column insert - disable explicit insert support
if (merge.HasIdentityInsert)
{
BuildIdentityInsert(merge.Target, false);
}
}
protected override void BuildMergeStatement(SqlMergeStatement merge)
{
if (!DB2iSeriesSqlProviderFlags.SupportsMergeStatement)
{
throw new LinqToDBException($"{Provider.Name} provider doesn't support SQL MERGE statement");
}
base.BuildMergeStatement(merge);
}
protected override void BuildMergeStatement(SqlMergeStatement merge)
{
// for identity column insert - enable explicit insert support
if (merge.HasIdentityInsert)
{
BuildIdentityInsert(merge.Target, true);
}
base.BuildMergeStatement(merge);
}
protected override void BuildMergeTerminator(SqlMergeStatement merge)
{
// merge command must be terminated with semicolon
StringBuilder.AppendLine(";");
// for identity column insert - disable explicit insert support
if (merge.HasIdentityInsert)
{
BuildIdentityInsert(merge.Target, false);
}
}
protected virtual void BuildMergeStatement(SqlMergeStatement merge)
{
BuildMergeInto(merge);
BuildMergeSource(merge);
BuildMergeOn(merge);
foreach (var operation in merge.Operations)
{
BuildMergeOperation(operation);
}
BuildMergeTerminator(merge);
}
protected override void BuildMergeInto(SqlMergeStatement merge)
{
StringBuilder.Append("MERGE ");
if (merge.Hint != null)
{
StringBuilder
.Append("{+ ")
.Append(merge.Hint)
.Append(" } ");
}
StringBuilder.Append("INTO ");
BuildTableName(merge.Target, true, true);
StringBuilder.AppendLine();
}
private void BuildMergeSourceEnumerable(SqlMergeStatement merge)
{
if (merge.Source.SourceEnumerable !.Rows.Count > 0)
{
StringBuilder.Append("(");
if (MergeSupportsSourceDirectValues)
{
BuildValues(merge.Source);
}
else
{
BuildValuesAsSelectsUnion(merge.Source.SourceFields, merge.Source.SourceEnumerable);
}
StringBuilder.Append(")");
}
protected virtual void BuildMergeStatement(SqlMergeStatement merge)
{
BuildTag(merge);
BuildWithClause(merge.With);
BuildMergeInto(merge);
BuildMergeSource(merge);
BuildMergeOn(merge);
foreach (var operation in merge.Operations)
{
BuildMergeOperation(operation);
}
BuildOutputSubclause(merge.Output);
BuildMergeTerminator(merge);
}
private void BuildMergeEmptySource(SqlMergeStatement merge)
{
StringBuilder
.AppendLine(OpenParens)
.Append("\tSELECT ")
;
for (var i = 0; i < merge.Source.SourceFields.Count; i++)
{
var field = merge.Source.SourceFields[i];
if (i > 0)
{
StringBuilder.Append(InlineComma);
}
if (IsSqlValuesTableValueTypeRequired(merge.Source.SourceEnumerable !, Array <ISqlExpression[]> .Empty, -1, i))
{
BuildTypedExpression(new SqlDataType(field), new SqlValue(field.Type, null));
}
protected override IBuildContext BuildMethodCall(ExpressionBuilder builder, MethodCallExpression methodCall, BuildInfo buildInfo)
{
// Merge(ITable<TTarget> target, string hint)
var target = builder.BuildSequence(new BuildInfo(buildInfo, methodCall.Arguments[0], new SelectQuery())
{
AssociationsAsSubQueries = true
});
var targetTable = ((TableBuilder.TableContext)target).SqlTable;
var merge = new SqlMergeStatement(targetTable)
{
Hint = (string?)methodCall.Arguments[1].EvaluateExpression()
};
target.SetAlias(merge.Target.Alias !);
target.Statement = merge;
return(new MergeContext(merge, target));
}
// TODO: both 2008 and 2012 builders inherit from same base class which leads to duplicate builder logic
// I think we should have single builder with versioning support as inheritance definitely suck for this case
protected override void BuildMergeInto(SqlMergeStatement merge)
{
StringBuilder
.Append("MERGE INTO ");
BuildTableName(merge.Target, true, false);
StringBuilder.Append(' ');
if (merge.Hint != null)
{
StringBuilder
.Append("WITH(")
.Append(merge.Hint)
.Append(") ");
}
BuildTableName(merge.Target, false, true);
StringBuilder.AppendLine();
}
protected override void BuildMergeInto(SqlMergeStatement merge)
{
StringBuilder.Append("MERGE");
StartStatementQueryExtensions(merge.SelectQuery);
StringBuilder.Append(' ');
if (merge.Hint != null)
{
if (HintBuilder !.Length > 0)
{
HintBuilder.Append(' ');
}
HintBuilder.Append(merge.Hint);
}
StringBuilder.Append("INTO ");
BuildTableName(merge.Target, true, true);
StringBuilder.AppendLine();
}
public MergeSourceQueryContext(SqlMergeStatement merge, IBuildContext sourceContext)
: base(sourceContext, new SelectQuery {
ParentSelect = sourceContext.SelectQuery
}, true)
{
_merge = merge;
_merge.Source = sourceContext is EnumerableContext enumerableSource
? new SqlMergeSourceTable()
{
SourceEnumerable = enumerableSource.Table
}
: new SqlMergeSourceTable()
{
SourceQuery = sourceContext.SelectQuery
};
if (SubQuery is SelectContext select)
{
select.AllowAddDefault = false;
}
}
public MergeContext(SqlMergeStatement merge, IBuildContext target)
: base(null, target, null)
{
Statement = merge;
}
public override void Visit(SqlMergeStatement codeObject)
{
}
/// <summary>
/// Allows to add text after generated merge command. E.g. to specify command terminator if provider requires it.
/// </summary>
protected virtual void BuildMergeTerminator(SqlMergeStatement merge)
{
}
public MergeContext(SqlMergeStatement merge, IBuildContext target, IBuildContext source)
: base(null, new[] { target, source }, null)
{
Statement = merge;
}
protected override void BuildMergeStatement(SqlMergeStatement merge)
{
throw new LinqToDBException($"{Name} provider doesn't support SQL MERGE statement");
}
public MergeContext(SqlMergeStatement merge, IBuildContext target, TableLikeQueryContext source)
: base(null, new[] { target, source }, null)
{
Statement = merge;
merge.Source = source.Source;
}
