private object VisitExpr([NotNull] SqlParser.ExprContext context, bool considerColumnAlias)
{
if (context.K_IN() != null && (context.in_list_expr() != null || context.factored_select_stmt() != null))
{
var result = new OperationExpression()
{
OperationType = OperationType.Binary,
Operator = context.K_NOT() != null ? "NOT IN" : "IN",
SubExpressions = new List <IExpression>()
};
result.SubExpressions.Add((IExpression)VisitExpr(context.expr(0)));
if (context.factored_select_stmt() != null)
{
var statement = (SelectStatement)VisitFactored_select_stmt(context.factored_select_stmt());
result.SubExpressions.Add(new SubQueryExpression()
{
Statement = statement
});
}
else
{
var listExpression = new ListExpression()
{
SubExpressions = new List <IExpression>()
};
result.SubExpressions.Add(listExpression);
foreach (var item in context.in_list_expr().expr())
{
listExpression.SubExpressions.Add((IExpression)VisitExpr(item));
}
}
return(result);
}
if (context.K_EXISTS() != null && context.factored_select_stmt() != null)
{
var statement = (SelectStatement)VisitFactored_select_stmt(context.factored_select_stmt());
var result = new OperationExpression()
{
OperationType = OperationType.Unary,
Operator = context.K_NOT() != null ? "NOT EXISTS" : "EXISTS",
SubExpressions = new List <IExpression>()
{
new SubQueryExpression()
{
Statement = statement,
}
}
};
return(result);
}
if (context.column_name() != null)
{
var table = context.table_name() == null ? "" : context.table_name().GetText();
var column = context.column_name().GetText();
var tableMap = queryTableStack.Peek();
var columMap = queryColumnStack.Peek();
if (considerColumnAlias && TryGetColumnExpressionByAlias(columMap, column, out var columnExpression))
{
return(columnExpression);
}
GetTableNameAlias(tableMap, table, out var tableName, out var tableAlias);
return(new ColumnExpression()
{
ColumnName = EscapeTableOrColumnName(column),
TableName = tableName,
TableAlias = tableAlias
});
}
if (context.function() != null)
{
var func = new FunctionExpression
{
FunctionName = context.function().function_name().GetText()
};
if (!GCSqlVisitorCheck.FunctionsDict.TryGetValue(func.FunctionName, out var parametersInfo))
{
throw new SQLParseException($"Not supported function '{func.FunctionName}'");
}
// parameter count check
var parameterCount = context.function().args_list()?.expr()?.Length ?? 0;
if (parameterCount < parametersInfo.Min || parameterCount > parametersInfo.Max)
{
if (parametersInfo.Min == parametersInfo.Max)
{
throw new SQLParseException($"Not '{func.FunctionName}' function accpet {parametersInfo.Max} parameter(s)");
}
else
{
throw new SQLParseException($"Not '{func.FunctionName}' function accpet {parametersInfo.Min} to {parametersInfo.Max} parameter(s)");
}
}
func.SubExpressions = new List <IExpression>();
if (context.function().args_list() != null)
{
if (context.function().args_list().GetText() == "*")
{
func.SubExpressions.Add(new KeywordExpression()
{
Keyword = context.function().args_list().GetText()
});
}
else
{
var exprList = context.function().args_list().expr();
if (exprList != null && exprList.Length != 0)
{
for (int i = 0; i < exprList.Length; i++)
{
var item = exprList[i];
IExpression argumentExpression = null;
var descriptor = parametersInfo.Descriptors != null && i < parametersInfo.Descriptors.Length ? parametersInfo.Descriptors[i] : null;
if (descriptor != null)
{
switch (descriptor.DescriptorType)
{
case ParameterDescriptorType.Enum:
var parameterText = item?.GetText();
if (!descriptor.CheckParameter(parameterText))
{
throw new SQLParseException($"'{parameterText}' is not a recognized datepart option.");
}
argumentExpression = new LiteralValueExpression()
{
Value = parameterText,
ValueType = LiteralValueType.String,
};
break;
default:
// do not need special handling.
break;
}
}
argumentExpression = argumentExpression ?? (IExpression)VisitExpr(item);
func.SubExpressions.Add(argumentExpression);
}
}
}
}
return(func);
}
if (context.unary_operator() != null)
{
var result = new OperationExpression()
{
OperationType = OperationType.Unary
};
result.Operator = context.unary_operator().GetText().ToUpper();
result.SubExpressions = new List <IExpression>
{
(IExpression)VisitExpr((SqlParser.ExprContext)context.unary_operator().Parent.GetChild(1))
};
// special handling for the not exists, in order to reduce the layer of the expression
if (result.SubExpressions.Count == 1 && (result.SubExpressions[0] as OperationExpression)?.Operator == "EXISTS")
{
((OperationExpression)result.SubExpressions[0]).Operator = "NOT EXISTS";
return(result.SubExpressions[0]);
}
return(result);
}
if (context.BIND_PARAMETER() != null)
{
return(new ParamExpression()
{
ParamName = context.GetText()
});
}
if (context.ChildCount == 1)
{
if (context.literal_value() != null)
{
var value = context.literal_value();
var text = value.GetText();
if (!string.IsNullOrEmpty(text) && text.StartsWith("'") && text.EndsWith("'"))
{
text = text.Substring(1, text.Length - 2);
}
var result = new LiteralValueExpression()
{
Value = text
};
if (value.NUMERIC_LITERAL() != null)
{
result.ValueType = LiteralValueType.Number;
}
else if (value.STRING_LITERAL() != null)
{
result.ValueType = LiteralValueType.String;
}
else if (value.NUMERIC_BOOLEAN() != null)
{
result.ValueType = LiteralValueType.Boolean;
}
else if (value.BLOB_LITERAL() != null)
{
result.ValueType = LiteralValueType.Blob;
}
else if (value.K_NULL() != null)
{
result.ValueType = LiteralValueType.Null;
}
return(result);
}
}
else if (context.ChildCount == 2)
{
if (context.K_ISNULL() != null)
{
var result = new OperationExpression()
{
OperationType = OperationType.Binary,
Operator = "IS"
};
result.SubExpressions = new List <IExpression>
{
(IExpression)VisitExpr((SqlParser.ExprContext)context.GetChild(0)),
new LiteralValueExpression()
{
ValueType = LiteralValueType.Null, Value = "NULL"
}
};
return(result);
}
}
else if (context.ChildCount == 3)
{
if (context.GetChild(0).GetText() == "(" && context.GetChild(2).GetText() == ")")
{
return(VisitExpr((SqlParser.ExprContext)context.GetChild(1)));
}
var result = new OperationExpression()
{
OperationType = OperationType.Binary
};
var op = context.GetChild(1).GetText().ToUpper();
switch (op)
{
case "AND":
case "OR":
case "*":
case "/":
case "+":
case "-":
case "=":
case "!=":
case "<>":
case ">":
case "<":
case ">=":
case "<=":
case "<<":
case ">>":
case "&":
case "|":
case "%":
case "LIKE":
{
result.Operator = op;
result.SubExpressions = new List <IExpression>
{
(IExpression)VisitExpr((SqlParser.ExprContext)context.GetChild(0)),
(IExpression)VisitExpr((SqlParser.ExprContext)context.GetChild(2))
};
}
break;
case "IS":
{
result.SubExpressions = new List <IExpression>()
{
(IExpression)VisitExpr((SqlParser.ExprContext)context.GetChild(0))
};
if (context.GetChild(2) is SqlParser.ExprContext exprContext)
{
if (exprContext.ChildCount == 2 && exprContext.unary_operator() != null && exprContext.unary_operator().K_NOT() != null && exprContext.GetChild(1).GetText().ToUpper() == "NULL")
{
result.Operator = "IS NOT";
result.SubExpressions.Add(new LiteralValueExpression()
{
Value = "NULL", ValueType = LiteralValueType.Null
});
}
else
{
result.Operator = op;
result.SubExpressions.Add((IExpression)VisitExpr((SqlParser.ExprContext)context.GetChild(2)));
}
}
else
{
result.Operator = op;
result.SubExpressions.Add((IExpression)VisitExpr((SqlParser.ExprContext)context.GetChild(2)));
}
}
break;
}
return(result);
}
else if (context.ChildCount == 4)
{
if (context.expr().Length == 2 &&
context.GetChild(1).GetText().ToUpper() == "NOT" &&
context.GetChild(2).GetText().ToUpper() == "LIKE")
{
var result = new OperationExpression()
{
OperationType = OperationType.Binary,
Operator = "NOT LIKE",
SubExpressions = new List <IExpression>()
{
(IExpression)VisitExpr(context.expr(0)),
(IExpression)VisitExpr(context.expr(1))
}
};
return(result);
}
}
else if (context.ChildCount == 5 &&
context.expr().Length == 3 &&
context.GetChild(1).GetText().ToUpper() == "BETWEEN" &&
context.GetChild(3).GetText().ToUpper() == "AND")
{
return(new BetweenExpression()
{
SubExpressions = new List <IExpression>()
{
(IExpression)VisitExpr(context.expr(0)),
(IExpression)VisitExpr(context.expr(1)),
(IExpression)VisitExpr(context.expr(2))
}
});
}
return(null);
}
/// <summary>
/// Visit a parse tree produced by <see cref="SqlParser.expr"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitExpr([NotNull] SqlParser.ExprContext context)
{
return(VisitChildren(context));
}
public override object VisitExpr([NotNull] SqlParser.ExprContext context)
{
return(VisitExpr(context, true));
}
