Postgresql SQLSTATE[42P18]: Indeterminate datatype with PDO and CONCAT

CONCAT is a function that takes a VARIADIC argument list, which means that internally postgres will convert them into an array of the same type.

postgres=# \df concat                          List of functions   Schema   |  Name  | Result data type | Argument data types | Type ------------+--------+------------------+---------------------+------ pg_catalog | concat | text             | VARIADIC "any"      | func

When trying to resolve the input type to a single type, the SQL parser fails. It can be reproduced in this simpler form:

postgres=# PREPARE p AS select concat('A', $1);ERROR:  could not determine data type of parameter $1

The parser can't figure out the datatype of $1 so it errs on the side of caution.

One easy solution is to cast the parameter as text:

postgres=# PREPARE p AS select concat($1::text);PREPARE

or with the CAST operator:

postgres=# PREPARE p AS select concat(cast($1 as text));PREPARE

I haven't tested with PDO but presumably it would work (given how it deals with parameters to produce prepared statements) to change the query to:

"...identification LIKE '%' || :identification || '::text%'..."

or use the '||' operator instead of concat in the query:

identification LIKE '%' || :identification || '%'

EDIT: BTW if you want to find that a parameter :X is a substring of identification, this clause is more secure: strpos(identification, :X) > 0, because :X may contain '%' or '_' without causing any side-effect in the match, contrary to what happens with LIKE.