private UpdateBuilder <T> InternalAppend(string field, Expression value)
{
if (!__sql.IsEmpty)
{
__sql.Append(", ");
}
__sql.AppendFormat("{0} = ", field);
base.Visit(value);
return(this);
}
private WhereBuilder Append(Expression property, QueryOperatorType op, object value, string type)
{
if (property != null && value != null)
{
if (!__sql.IsEmpty)
{
__sql.Append(type);
}
__sql.Append("(");
__sql.Append(__db.GetColumnName(property));
__sql.Append(this.GetOperator(op));
__sql.AppendFormat("@{0}", this.Params.Count);
__sql.Append(")");
switch (op)
{
case QueryOperatorType.Contains:
value = "%" + value.ToString().Trim('%') + "%";
break;
case QueryOperatorType.StartsWith:
value = value.ToString().Trim('%') + "%";
break;
case QueryOperatorType.EndsWith:
value = "%" + value.ToString().Trim('%');
break;
}
this.Params.Add(value);
}
return(this);
}
private void ParseExists(MethodCallExpression expression, bool isNotExists)
{
var value = this.GetRightValue(expression.Arguments[1]);
if (value is IGetBuilder)
{
var val = value as IGetBuilder;
__select.AppendFormat("({1} Exists ({0}))", val.GetSql(context.Parameters), isNotExists ? "NOT" : "");
}
}
private GetBuilder <T> InternalJoin <TJoin>(string join, Expression expression) where TJoin : IModel
{
if (__join.IsNull())
{
__join = new STR();
}
__join.AppendFormat(" {0} {1} ON {2} ",
join, database.GetTableName <TJoin>(),
new JoinBuilder(context).Append(expression).ToString());
return(this);
}
/// <summary>
/// 处理字段或属性表达式
/// </summary>
/// <param name="expression">表达式</param>
/// <returns>表达式</returns>
protected override Expression VisitMemberAccess(MemberExpression expression)
{
if (!__sql.IsEmpty)
{
__sql.Append(", ");
}
if (IsParameterOrConstant(expression))
{
if (IsDateTimeProperty(expression))
{
ParseDateTimeProperty(expression);
}
else
{
__sql.Append(this.GetColumnName(withTableName, context.Database, expression));
}
}
else
{
__sql.AppendFormat("@{0}", context.Parameters.Count);
context.Parameters.Add(this.GetRightValue(expression));
}
return(expression);
}
/// <summary>
/// 处理字段或属性表达式
/// </summary>
/// <param name="expression">表达式</param>
/// <returns>表达式</returns>
protected override Expression VisitMemberAccess(MemberExpression expression)
{
if (!select.IsEmpty && __needdelimiter)
{
select.Append(", ");
}
if (IsParameterOrConstant(expression))
{
if (IsDateTimeProperty(expression))
{
ParseDateTimeProperty(expression);
}
else
{
select.Append(this.GetColumnName(whitTableName, context.Database, expression));
}
}
else
{
var value = this.GetRightValue(expression);
if (value is IGetBuilder)
{
select.Append((value as IGetBuilder).GetSql(context.Parameters));
}
else
{
if (value.IsValue_())
{
select.Append(value);
}
else
{
select.AppendFormat("'{0}'", value);
}
}
}
return(expression);
}
/// <summary>
/// 处理二元运算表达式
/// </summary>
/// <param name="expression">表达式</param>
/// <returns>表达式</returns>
protected override Expression VisitBinary(BinaryExpression expression)
{
if (expression.Right is ConstantExpression && (expression.NodeType == ExpressionType.Equal || expression.NodeType == ExpressionType.NotEqual))
{//X == null or X !=null
var constant = expression.Right as ConstantExpression;
MemberExpression member = null;
if (expression.Left is MemberExpression)
{
member = expression.Left as MemberExpression;
}
if (expression.Left is UnaryExpression)
{
if (((UnaryExpression)expression.Left).Operand is MemberExpression)
{
member = ((UnaryExpression)expression.Left).Operand as MemberExpression;
}
}
if (member != null && constant.Value == null)
{
if (expression.NodeType == ExpressionType.Equal)
{
__sql.AppendFormat("( {0} IS NULL )", this.GetColumnName(withTableName, Database, member));
}
else
{
__sql.AppendFormat("( {0} IS NOT NULL )", this.GetColumnName(withTableName, Database, member));
}
return(expression);
}
}
__sql.Append("(");
this.Visit(expression.Left);
__sql.Append(this.GetOperator(expression.NodeType));
this.Visit(expression.Right);
__sql.Append(")");
return(expression);
}
