/// <summary>
/// Visit match expression
/// </summary>
/// <param name="matchExpression"></param>
/// <returns></returns>
public Expression VisitMatch([NotNull] MatchExpression expression)
{
Check.NotNull(expression, nameof(expression));
var optional = expression.Optional
? "OPTIONAL "
: String.Empty;
_commandBuilder
.Append($"{optional}MATCH ");
Visit(expression.Pattern);
if (!(expression.Where is null))
{
// TODO: optimize where
_commandBuilder
.AppendLine()
.Append("WHERE ");
Visit(expression.Where);
}
return(expression);
}
protected override Expression VisitSelect(SelectExpression selectExpression)
{
IDisposable subQueryIndent = null;
if (selectExpression.Alias != null)
{
_relationalCommandBuilder.AppendLine("(");
subQueryIndent = _relationalCommandBuilder.Indent();
}
if (selectExpression.IsSetOperation)
{
GenerateSetOperation(selectExpression);
}
else
{
GenerateSelect(selectExpression);
}
if (selectExpression.Alias != null)
{
subQueryIndent.Dispose();
_relationalCommandBuilder.AppendLine()
.Append(") AS " + _sqlGenerationHelper.DelimitIdentifier(selectExpression.Alias));
}
return(selectExpression);
}
/// <summary>
/// Appends an object, that contains multiple lines of text, to the command text.
/// Each line read from the object is appended on a new line.
/// </summary>
/// <param name="commandBuilder">The command builder.</param>
/// <param name="value">The object to be written.</param>
/// <param name="skipFinalNewline">If <see langword="true" />, then the final newline character is skipped.</param>
/// <returns>The same builder instance so that multiple calls can be chained.</returns>
public static IRelationalCommandBuilder AppendLines(
this IRelationalCommandBuilder commandBuilder,
string value,
bool skipFinalNewline = false)
{
using (var reader = new StringReader(value))
{
var first = true;
string?line;
while ((line = reader.ReadLine()) != null)
{
if (first)
{
first = false;
}
else
{
commandBuilder.AppendLine();
}
if (line.Length != 0)
{
commandBuilder.Append(line);
}
}
}
if (!skipFinalNewline)
{
commandBuilder.AppendLine();
}
return(commandBuilder);
}
/// <summary>
/// Appends an object, that contains multiple lines of text, to the command text.
/// Each line read from the object is appended on a new line.
/// </summary>
/// <param name="commandBuilder"> The command builder. </param>
/// <param name="value"> The object to be written. </param>
/// <param name="skipFinalNewline"> If <code>true</code>, then the final newline character is skipped. </param>
/// <returns> The same builder instance so that multiple calls can be chained. </returns>
public static IRelationalCommandBuilder AppendLines(
[NotNull] this IRelationalCommandBuilder commandBuilder,
[NotNull] object value,
bool skipFinalNewline = false)
{
Check.NotNull(commandBuilder, nameof(commandBuilder));
Check.NotNull(value, nameof(value));
using (var reader = new StringReader(value.ToString()))
{
var first = true;
string line;
while ((line = reader.ReadLine()) != null)
{
if (first)
{
first = false;
}
else
{
commandBuilder.AppendLine();
}
if (line.Length != 0)
{
commandBuilder.Append(line);
}
}
}
if (!skipFinalNewline)
{
commandBuilder.AppendLine();
}
return(commandBuilder);
}
protected virtual void GenerateTagsHeaderComment(SelectExpression selectExpression)
{
if (selectExpression.Tags.Count > 0)
{
foreach (var tag in selectExpression.Tags)
{
using (var reader = new StringReader(tag))
{
string line;
while ((line = reader.ReadLine()) != null)
{
_relationalCommandBuilder.Append(SingleLineCommentToken).Append(" ").AppendLine(line);
}
}
_relationalCommandBuilder.AppendLine();
}
}
}
protected override Expression VisitSelect(SelectExpression selectExpression)
{
Check.NotNull(selectExpression, nameof(selectExpression));
if (IsNonComposedSetOperation(selectExpression))
{
// Naked set operation
GenerateSetOperation((SetOperationBase)selectExpression.Tables[0]);
return(selectExpression);
}
IDisposable subQueryIndent = null;
if (selectExpression.Alias != null)
{
_relationalCommandBuilder.AppendLine("(");
subQueryIndent = _relationalCommandBuilder.Indent();
}
_relationalCommandBuilder.Append("SELECT ");
if (selectExpression.IsDistinct)
{
_relationalCommandBuilder.Append("DISTINCT ");
}
GenerateTop(selectExpression);
if (selectExpression.Projection.Any())
{
GenerateList(selectExpression.Projection, e => Visit(e));
}
else
{
_relationalCommandBuilder.Append("1");
}
if (selectExpression.Tables.Any())
{
_relationalCommandBuilder.AppendLine().Append("FROM ");
GenerateList(selectExpression.Tables, e => Visit(e), sql => sql.AppendLine());
}
else
{
GeneratePseudoFromClause();
}
if (selectExpression.Predicate != null)
{
_relationalCommandBuilder.AppendLine().Append("WHERE ");
Visit(selectExpression.Predicate);
}
if (selectExpression.GroupBy.Count > 0)
{
_relationalCommandBuilder.AppendLine().Append("GROUP BY ");
GenerateList(selectExpression.GroupBy, e => Visit(e));
}
if (selectExpression.Having != null)
{
_relationalCommandBuilder.AppendLine().Append("HAVING ");
Visit(selectExpression.Having);
}
GenerateOrderings(selectExpression);
GenerateLimitOffset(selectExpression);
if (selectExpression.Alias != null)
{
subQueryIndent.Dispose();
_relationalCommandBuilder.AppendLine()
.Append(")" + AliasSeparator + _sqlGenerationHelper.DelimitIdentifier(selectExpression.Alias));
}
return(selectExpression);
}
protected override Expression VisitSelect(SelectExpression selectExpression)
{
IDisposable subQueryIndent = null;
if (!string.IsNullOrEmpty(selectExpression.Alias))
{
_relationalCommandBuilder.AppendLine("(");
subQueryIndent = _relationalCommandBuilder.Indent();
}
_relationalCommandBuilder.Append("SELECT ");
if (selectExpression.IsDistinct)
{
_relationalCommandBuilder.Append("DISTINCT ");
}
GenerateTop(selectExpression);
if (selectExpression.Projection.Any())
{
GenerateList(selectExpression.Projection, e => Visit(e));
}
else
{
_relationalCommandBuilder.Append("1");
}
if (selectExpression.Tables.Any())
{
_relationalCommandBuilder.AppendLine()
.Append("FROM ");
GenerateList(selectExpression.Tables, e => Visit(e), sql => sql.AppendLine());
}
if (selectExpression.Predicate != null)
{
_relationalCommandBuilder.AppendLine()
.Append("WHERE ");
Visit(selectExpression.Predicate);
}
if (selectExpression.Orderings.Any())
{
var orderings = selectExpression.Orderings.ToList();
if (selectExpression.Limit == null &&
selectExpression.Offset == null)
{
orderings.RemoveAll(oe => oe.Expression is SqlConstantExpression || oe.Expression is SqlParameterExpression);
}
if (orderings.Count > 0)
{
_relationalCommandBuilder.AppendLine()
.Append("ORDER BY ");
GenerateList(orderings, e => Visit(e));
}
}
else if (selectExpression.Offset != null)
{
_relationalCommandBuilder.AppendLine()
.Append("ORDER BY (SELECT 1)");
}
GenerateLimitOffset(selectExpression);
if (!string.IsNullOrEmpty(selectExpression.Alias))
{
subQueryIndent.Dispose();
_relationalCommandBuilder.AppendLine()
.Append(") AS " + _sqlGenerationHelper.DelimitIdentifier(selectExpression.Alias));
}
return(selectExpression);
}
public static Expression VisitSelect(IZackQuerySqlGenerator sqlGenerator, ISqlGenerationHelper _sqlGenerationHelper, SelectExpression selectExpression)
{
if (BatchUtils.IsNonComposedSetOperation(selectExpression))
{
sqlGenerator.P_GenerateSetOperation((SetOperationBase)selectExpression.Tables[0]);
return(selectExpression);
}
IRelationalCommandBuilder Sql = sqlGenerator.P_Sql;
IDisposable disposable = null;
if (selectExpression.Alias != null)
{
Sql.AppendLine("(");
disposable = sqlGenerator.P_Sql.Indent();
}
Sql.Append("SELECT ");
if (selectExpression.IsDistinct)
{
Sql.Append("DISTINCT ");
}
sqlGenerator.P_GenerateTop(selectExpression);
if (selectExpression.Projection.Any())
{
BatchUtils.GenerateList(selectExpression.Projection, Sql, delegate(ProjectionExpression e)
{
var oldSQL = Sql.Build().CommandText; //zack's code
sqlGenerator.Visit(e);
string column = BatchUtils.Diff(oldSQL, Sql.Build().CommandText); //zack's code
sqlGenerator.ProjectionSQL.Add(column); //zack's code
});
}
else
{
Sql.Append("1");
sqlGenerator.ProjectionSQL.Add("1"); //zack's code
}
if (selectExpression.Tables.Any())
{
Sql.AppendLine().Append("FROM ");
BatchUtils.GenerateList(selectExpression.Tables, Sql, delegate(TableExpressionBase e)
{
sqlGenerator.Visit(e);
}, delegate(IRelationalCommandBuilder sql)
{
sql.AppendLine();
});
}
else
{
sqlGenerator.P_GeneratePseudoFromClause();
}
if (selectExpression.Predicate != null)
{
Sql.AppendLine().Append("WHERE ");
var oldSQL = Sql.Build().CommandText; //zack's code
sqlGenerator.Visit(selectExpression.Predicate);
sqlGenerator.PredicateSQL = BatchUtils.Diff(oldSQL, Sql.Build().CommandText); //zack's code
}
if (selectExpression.GroupBy.Count > 0)
{
Sql.AppendLine().Append("GROUP BY ");
BatchUtils.GenerateList(selectExpression.GroupBy, Sql, delegate(SqlExpression e)
{
sqlGenerator.Visit(e);
});
}
if (selectExpression.Having != null)
{
Sql.AppendLine().Append("HAVING ");
sqlGenerator.Visit(selectExpression.Having);
}
sqlGenerator.P_GenerateOrderings(selectExpression);
sqlGenerator.P_GenerateLimitOffset(selectExpression);
if (selectExpression.Alias != null)
{
disposable.Dispose();
Sql.AppendLine().Append(")" + sqlGenerator.P_AliasSeparator + _sqlGenerationHelper.DelimitIdentifier(selectExpression.Alias));
}
return(selectExpression);
}
/// <summary>
/// Starts a new line on the command being built.
/// </summary>
/// <returns> This builder so that additional calls can be chained. </returns>
public virtual MigrationCommandListBuilder AppendLine()
{
_commandBuilder.AppendLine();
return(this);
}
public virtual RelationalCommandListBuilder AppendLine()
{
_commandBuilder.AppendLine();
return(this);
}
/// <summary>
/// 添加行
/// </summary>
/// <returns></returns>
public override MigrationCommandListBuilder AppendLine()
{
_commandBuilder.AppendLine();
return(this);
}
