Question

Right now i have 100 tables in SQL and i am looking for a specific string value in all tables, and i do not know which column it is in.

select * from table1, table2 where column1 = 'MyLostString' will not work because i do not know which column it has to be in.

Is there a SQL query for that, must i brute force search every table for every column for that ‘MyLostString’

If I were to brute-force search across all tables, is there an efficient query for that?
For instance:

select * from table3 where allcolumns = MyLostString

Answer 1

It is the defining feature of a RDBMS (or at least one of them), that the meaning of a value depends on the column it is in. E.g.: The value 17 will have quite different meanings, if it stands in a customer_id column, than in the product_id of a fictional orders table.

This leads to the fact, that RDBMS are not well equipped to search for a value, no matter in which column of which tables it might be used.

My recommendation is to first study the data model to try and find out, which column of which table should be holding the value. If this really fails, you have a problem much worse than a “lost string”.

The last ressort is to transform the DB into something better suited for fulltext search … such as a flat file. You might want to try mydbexportcommand --options | grep -C10 'My lost string' or friends.