Execute MySQL script in grails app - mysql

Question

I have an MySQL Script I want to execute in a controller when my Grails 3.0.9 application is running. I've tried it this way:
import groovy.sql.Sql
import grails.util.Holders
def void clearDatabase() {
String sqlFilePath = 'path/to/file/clear_database.sql'
String sqlString = new File(sqlFilePath).text
def sql = Sql.newInstance(Holders.config.dataSource.url, Holders.config.dataSource.username, Holders.config.dataSource.password, Holders.config.dataSource.driverClassName)
sql.execute(sqlString)
}
Thats how my clear_database.sql file looks like:
SET FOREIGN_KEY_CHECKS = 0;
TRUNCATE table_a;
TRUNCATE table_b;
TRUNCATE table_c;
SET FOREIGN_KEY_CHECKS = 1;
Thats the error message I get:
WARN org.hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Warning Code: 1064, SQLState: 42000
com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'TRUNCATE table_a;
Is my MySQL syntax wrong or am I missing something else?
edit:
When I run the script manually it works. So I think the script is correct but the way I execute it not.

Answer 1

The problem was that sql.execute(sqlString) wants a GString and I've given it a normal String so it added quotes and the result was an incorrect MySQL syntax like described here.
That's how it works for me:
def sql = Sql.newInstance(Holders.config.dataSource.url, Holders.config.dataSource.username, Holders.config.dataSource.password, Holders.config.dataSource.driverClassName)
sql.execute "SET FOREIGN_KEY_CHECKS = 0;"
sql.execute "truncate ${Sql.expand("table_a")}"
sql.execute "truncate ${Sql.expand("table_b")}"
sql.execute "truncate ${Sql.expand("table_c")}"
sql.execute "SET FOREIGN_KEY_CHECKS = 1;"
There is no clear_database.sql file needed anymore.

Answer 2

Not sure but could you try: as your clear_database.sql
SET FOREIGN_KEY_CHECKS = 0;
TRUNCATE TABLE table_a;
TRUNCATE TABLE table_b;
TRUNCATE TABLE table_c;
SET FOREIGN_KEY_CHECKS = 1;
Good luck!!