Some time we need to get all tables which have primary key constraints. There are many way to get this information.
ISTC.Table_Catalog as BD_Name,
ISTC.Table_Schema AS TBL_SCHEMA,
ISTC.Table_Name AS TBL_NAME,
ISCCU.Column_Name AS COL_NAME,
ISTC.Constraint_Name AS CONSTRAINT_NAME
This one is the best query to find out the tables which have primary key because information schema provides more information and all the data can be retrieved with the filtered filter.