How to search the entire database for column name equal to my rule and specific value as well.
Let’s say that i want to search for column name like voucher
where it’s value contain that word value10
So far i can find the column name but i don’t know how to match with value as well.
SELECT column_name FROM information_schema.columns WHERE TABLE_SCHEMA = 'dbname' AND column_name LIKE '%voucher%'
So the end goal is to find any column name like voucher
containing value10
within it’s content.
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Answer
Create a stored procedure to loop through meta data table INFORMATION_SCHEMA to fetch all tables with column_name of choice. Further dynamic SQL is used to scan each of the tables retrieved for columns having the value of choice.
DDL and DML for setting the data for testing :
create table TESTA(COLMNA char(255),COLMNC char(255)); create table TESTB(COLMNA char(255),COLMNB char(255)); create table TESTC(COLMND char(255),COLMNA char(255)); insert into TESTA values('value0','someothercolmn'); insert into TESTB values('value0','anothersomeothercolmn'); insert into TESTB values('value1','Yetanothercolumn');
Test is to search all tables having column_name as COLMNA
with value as value0
. The procedure will accept column_name and column_Value, hence can be used across the database, just need to pass values as appropriate.
CREATE PROCEDURE Findtables( colmn_name VARCHAR(64),colmn_value VARCHAR(64) ) BEGIN DECLARE tablename CHAR(64); DECLARE c1 CURSOR FOR SELECT table_name FROM information_Schema WHERE column_name = colmn_name; OPEN c1; lable_loop:LOOP FETCH c1 INTO tablename; select tablename; SET @sql = CONCAT('SELECT * FROM ', tablename, ' WHERE ',colmn_name,' = "',colmn_value ,'" ;'); PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt; END LOOP lable_loop; CLOSE c1; END;
Call the stored procedure :
CALL Findtables('COLMNA','value0');
Output :
tablename TESTA COLMNA COLMNC value0 someothercolmn tablename TESTB COLMNA COLMNB value0 anothersomeothercolmn tablename TESTC COLMND COLMNA
Demonstration of the solution can be found in DBFIDDLE link [https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=4888a6160faf97fb75665832d6610293][1]
PS : I have to create INFORMATION_SCHEMA table in dbfiddle as metadata tables are not accessible.