columnA like %columnB

I’m trying to do select * where column1 = % column2 %.

this is my query

select ticket_cp, id_con, raison_sociale, date, Type, RSP
from en_cours,
     Base_Client 
where Base_Client.Client like '%'+raison_sociale+ '%' 

The error:

The data types varchar and text are incompatible in the add operator.

Answer

You can cast the text to a varchar(max):

select ticket_cp, id_con, raison_sociale, date, Type, RSP 
from en_cours e
inner join base_Client b 
    on  b.Client like '%'+ cast(e.raison_sociale as varchar(max)) + '%' 

Or, if b.Client is a text too:

    on  cast(b.Client as varchar(max)) 
        like   '%'+ cast(e.raison_sociale as varchar(max)) + '%' 

Notes (most of which already were commented):

• text is deprecated; you want to use nvarchar(max) (or nvarchar(max)) instead

• always use explicit, standard joins (with the on keyword) instead of implicit, old-school joins (with commas in the from clause)

• columns in the select clause should be qualified with the alias of the table they belong to in order to avoid any ambiguity