/// <summary>Определение параметра</summary>
public static Expr Param(string paramName)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Parameter(paramName);
return(oper);
}
/// <summary>Определение проверки на NULL</summary>
public static Expr IfNull(Expr test, Expr val)
{
Expr oper = new Expr();
oper.Expression = OmExpression.IfNull(test.Expression, val.Expression);
return(oper);
}
/// <summary>Определение функции</summary>
public static Expr Function(AggFunc func, Expr val)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Function(func, val.Expression);
return(oper);
}
/// <summary>Определение поля</summary>
public static Expr Field(string fieldName, From from)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Field(fieldName, from != null ? from.Term : null);
return(oper);
}
/// <summary>Определение константы (DateTime)</summary>
public static Expr Date(DateTime val)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Date(val);
return(oper);
}
/// <summary>Произвольный SQL кон</summary>
public static Expr Raw(string sqlText)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Raw(sqlText);
return(oper);
}
/// <summary>Определение поля</summary>
public static Expr Field(string fieldName)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Field(fieldName);
return(oper);
}
/// <summary>Определение константы (string)</summary>
public static Expr String(string val)
{
Expr oper = new Expr();
oper.Expression = OmExpression.String(val);
return(oper);
}
/// <summary>Определение подзапроса</summary>
public static Expr SubQuery(Select subQuery)
{
Expr oper = new Expr();
oper.Expression = OmExpression.SubQuery(subQuery.Query);
return(oper);
}
/// <summary>Определение константы (double)</summary>
public static Expr Num(double val)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Number(val);
return(oper);
}
/// <summary>Определение константы</summary>
internal static Expr Constant(DataType type, object val)
{
Expr oper = new Expr();
oper.Expression = OmExpression.Constant(type, val);
return(oper);
}
/// <summary>Определение NULL</summary>
public static Expr Null()
{
Expr oper = new Expr();
oper.Expression = OmExpression.Null();
return(oper);
}
static Cond CreateNotLikeCompare(OmExpression expr1, OmExpression expr2, char escapeChar)
{
Cond oper = new Cond();
oper.Term = WhereTerm.CreateNotLikeCompare(expr1, expr2, escapeChar);
return(oper);
}
/// <summary>
/// Renders IfNull OmExpression
/// </summary>
/// <param name="builder"></param>
/// <param name="expr"></param>
protected override void IfNull(StringBuilder builder, OmExpression expr)
{
builder.Append("isnull(");
Expression(builder, expr.SubExpr1);
builder.Append(", ");
Expression(builder, expr.SubExpr2);
builder.Append(")");
}
/// <summary>
/// Renders OmExpression
/// </summary>
/// <param name="builder"></param>
/// <param name="expr"></param>
protected virtual void Expression(StringBuilder builder, OmExpression expr)
{
OmExpressionType type = expr.Type;
if (type == OmExpressionType.Field)
{
QualifiedIdentifier(builder, expr.TableAlias, expr.Value.ToString());
}
else if (type == OmExpressionType.Function)
{
Function(builder, expr.AggFunction, expr.SubExpr1);
}
else if (type == OmExpressionType.Constant)
{
Constant(builder, (OmConstant)expr.Value);
}
else if (type == OmExpressionType.SubQueryText)
{
builder.AppendFormat("({0})", (string)expr.Value);
}
else if (type == OmExpressionType.SubQueryObject)
{
builder.AppendFormat("({0})", RenderSelect((SelectQuery)expr.Value));
}
else if (type == OmExpressionType.PseudoField)
{
builder.AppendFormat("{0}", (string)expr.Value);
}
else if (type == OmExpressionType.Parameter)
{
builder.AppendFormat("{0}{1}", ParameterPrefix, (string)expr.Value);
}
else if (type == OmExpressionType.Raw)
{
builder.AppendFormat("{0}", (string)expr.Value);
}
else if (type == OmExpressionType.Case)
{
CaseClause(builder, expr.CaseClause);
}
else if (type == OmExpressionType.IfNull)
{
IfNull(builder, expr);
}
else if (type == OmExpressionType.Null)
{
builder.Append("null");
}
else
{
throw new InvalidQueryException("Unkown expression type: " + type.ToString());
}
}
/// <summary> /// Renders IfNull OmExpression /// </summary> /// <param name="builder"></param> /// <param name="expr"></param> protected abstract void IfNull(StringBuilder builder, OmExpression expr);
/// <summary>
/// Renders a OmExpression of type Function
/// </summary>
/// <param name="builder"></param>
/// <param name="func"></param>
/// <param name="param"></param>
protected virtual void Function(StringBuilder builder, AggFunc func, OmExpression param)
{
builder.AppendFormat("{0}(", func.ToStringFast()); // .ToString());
Expression(builder, param);
builder.AppendFormat(")");
}
