How to find all the tables in MySQL with specific column names in them?

Question

I have 2-3 different column names that I want to look up in the entire DB and list out all tables which have those columns. Any easy script?

Answer 1

To get all tables with columns columnA or ColumnB in the database YourDatabase:

SELECT DISTINCT TABLE_NAME 
    FROM INFORMATION_SCHEMA.COLUMNS
    WHERE COLUMN_NAME IN ('columnA','ColumnB')
        AND TABLE_SCHEMA='YourDatabase';

Answer 2

For those searching for the inverse of this, i.e. looking for tables that do not contain a certain column name, here is the query...

SELECT DISTINCT TABLE_NAME FROM information_schema.columns WHERE 
TABLE_SCHEMA = 'your_db_name' AND TABLE_NAME NOT IN (SELECT DISTINCT 
TABLE_NAME FROM information_schema.columns WHERE column_name = 
'column_name' AND TABLE_SCHEMA = 'your_db_name');

This came in really handy when we began to slowly implement use of InnoDB's special ai_col column and needed to figure out which of our 200 tables had yet to be upgraded.

Answer 3

select distinct table_name 
from information_schema.columns 
where column_name in ('ColumnA') 
and table_schema='YourDatabase';
and table_name in 
(
 select distinct table_name 
 from information_schema.columns 
 where column_name in ('ColumnB')
 and table_schema='YourDatabase';
);

That ^^ will get the tables with ColumnA AND ColumnB instead of ColumnA OR ColumnB like the accepted answer

Answer 4

In version that do not have information_schema (older versions, or some ndb's) you can dump the table structure and search the column manually.

mysqldump -h$host -u$user -p$pass --compact --no-data --all-databases > some_file.sql

Now search the column name in some_file.sql using your preferred text editor, or use some nifty awk scripts.

---

And a simple sed script to find the column, just replace COLUMN_NAME with your's:

sed -n '/^USE/{h};/^CREATE/{H;x;s/\nCREATE.*\n/\n/;x};/COLUMN_NAME/{x;p};' <some_file.sql
USE `DATABASE_NAME`;
CREATE TABLE `TABLE_NAME` (
  `COLUMN_NAME` varchar(10) NOT NULL,

You can pipe the dump directly in sed but that's trivial.

Answer 5

The problem with information_schema is that it can be terribly slow. It is faster to use the SHOW commands.

After you select the database you first send the query SHOW TABLES. And then you do SHOW COLUMNS for each of the tables.

In PHP that would look something like

    $res = mysqli_query("SHOW TABLES");
    while($row = mysqli_fetch_array($res))
    {   $rs2 = mysqli_query("SHOW COLUMNS FROM ".$row[0]);
        while($rw2 = mysqli_fetch_array($rs2))
        {   if($rw2[0] == $target)
               ....
        }
    }