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Aetos2501
Asked: 2020-01-25 17:14:42 +0800 CST 2020-01-25 17:14:42 +0800 CST

SQL SERVER conversion error "Conversion failed when converting the varchar value to bit" in a query?

  • 772

The following query shows me a

error Conversion failed when converting the varchar value 'IF EXISTS' to data type bit.

I don't know how to solve it, column4 is of type BIT but sometimes I want to obtain the type bit and sometimes I want to obtain a text so that it has more meaning for the user, I control that with a variable called @TextoOrBit.

Thank you very much in advance for your support and if you can guide me on how to obtain the desired result.

DECLARE 
   @TextoOrBit BIT

SET @TextoOrBit = 0;

 SELECT 
   COLUMNA1,
   COLUMNA2,
   COLUMNA3,
   CASE @TextoOrBit 
      WHEN 1 THEN 
          CASE COLUMNA4 WHEN 1 THEN 'SI EXISTE' ELSE 'NO EXISTE' END
      ELSE 
          CASE COLUMNA4 WHEN 1 THEN CAST(1 AS BIT) ELSE CAST(1 AS BIT) END
   END AS  COLUMNA4_custom
 FROM
   TABLA_DATOS
c#

1 Answers

  1. Best Answer

    If you define a class for the List<>, you can execute the query only once and have properties

    public class Class1{

   //otras propiedades      

   public bool COLUMNA4 {get;set;}

   public string COLUMNA4Text
   {
      get { return this.COLUMNA4 ? "SI EXISTE" : "NO EXISTE"; }
   }
}

    from the query you get the value bitof the field that of course in c# is a bool, but then for the text you only expose a property readonlythat allows you to obtain the text that you will show to the user and everything is encapsulated in the class

    • 1