# I can't get foreign keys to work in MySQL **URL:** \ **Category:** Liquibase Development\ **Created:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412 "2010-06-29T20:18:00Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![cpjust](https://avatars.discourse-cdn.com/v4/letter/c/74df32/32.png) [@cpjust](https://forum.liquibase.org/u/cpjust)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/1 "2010-06-29T20:18:00Z")
Hi, I can’t see much difference between these 2 SQL scripts, but the one created by Liquibase adds UNIQUE constraints after the table is created instead of doing it as part of the CREATE TABLE statement.  For some reason, when I run the Liquibase version on MySQL the foreign keys don’t get created, even though I see an ALTER TABLE statement that adds the foreign key. Here is the version that Liquibase creates: -- \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* -- Update Database Script -- \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* -- Change Log: /tmp/changelog.xml -- Ran at: 29/06/10 12:53 PM -- Against: root@localhost@jdbc:mysql://localhost:3306/TEST\_SCHEMA -- LiquiBase version: 2.0-rc2-SNAPSHOT -- \*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\*\* – Changeset /tmp/changelog.xml::1277830437442-1::root (generated)::(Checksum: 2:32bfb63aab569f7cff744d807770ad27) CREATE TABLE `TEST_SCHEMA`.`NOT_NULL_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_ID` INT NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `BIGINT_` BIGINT NOT NULL, `BLOB_1MB` BLOB NOT NULL, `CHAR_1` CHARACTER(1) NOT NULL, `CLOB_1MB` TEXT NOT NULL, `DATE_` DATE NOT NULL, `DECIMAL_5_0` DECIMAL(5,0) NOT NULL, `DOUBLE_` DOUBLE NOT NULL, `INTEGER_` INT NOT NULL, `REAL_` DOUBLE NOT NULL, `SMALLINT_` SMALLINT NOT NULL, `TIME_` TIME NOT NULL, `TIMESTAMP_` DATETIME NOT NULL, `VARCHAR_50` VARCHAR(50) NOT NULL, CONSTRAINT `PK_NOT_NULL_TBL` PRIMARY KEY (`INTEGER_PK`)); – Changeset /tmp/changelog.xml::1277830437442-2::root (generated)::(Checksum: 2:74fc205b8cef2b6c47316e6226499e9f) CREATE TABLE `TEST_SCHEMA`.`NULL_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_ID` INT NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `BIGINT_` BIGINT, `BLOB_1MB` BLOB, `CHAR_1` CHARACTER(1), `CLOB_1MB` TEXT, `DATE_` DATE, `DECIMAL_5_0` DECIMAL(5,0), `DOUBLE_` DOUBLE, `INTEGER_` INT, `REAL_` DOUBLE, `SMALLINT_` SMALLINT, `TIME_` TIME, `TIMESTAMP_` DATETIME, `VARCHAR_50` VARCHAR(50), CONSTRAINT `PK_NULL_TBL` PRIMARY KEY (`INTEGER_PK`)); – Changeset /tmp/changelog.xml::1277830437442-3::root (generated)::(Checksum: 2:9115beeb6d8eeaa1daa6f281e2325a5a) CREATE TABLE `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_ID` INT NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `BIGINT_` BIGINT DEFAULT 1, `CHAR_1` CHARACTER(1) DEFAULT ‘a’, `CLOB_1MB` TEXT, `DATE_` DATE, `DECIMAL_5_5` DECIMAL(5,5) DEFAULT 0, `DOUBLE_` DOUBLE DEFAULT 3.14, `INTEGER_` INT DEFAULT 1, `REAL_` DOUBLE DEFAULT 3.14, `SMALLINT_` SMALLINT DEFAULT 1, `TIME_` TIME, `TIMESTAMP_` DATETIME, `VARCHAR_50` VARCHAR(50) DEFAULT ‘abc123’, CONSTRAINT `PK_NULL_WITH_DEFAU` PRIMARY KEY (`INTEGER_PK`)); – Changeset /tmp/changelog.xml::1277830437442-4::root (generated)::(Checksum: 2:f1d39d91e42b5c298fb65ca6b7887acf) CREATE TABLE `TEST_SCHEMA`.`SMALL_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `INTEGER_` INT, CONSTRAINT `PK_SMALL_TBL` PRIMARY KEY (`INTEGER_PK`)); – Changeset /tmp/changelog.xml::1277830437442-5::root (generated)::(Checksum: 2:53fc6636db9cc10bea2e74c91d9243a6) CREATE TABLE `TEST_SCHEMA`.`SMALL_TBL_NO_PK` (`INTEGER_` INT NOT NULL); – Changeset /tmp/changelog.xml::1277830437442-6::root (generated)::(Checksum: 2:2be4097154489e3cbd40e5f78c65cb13) ALTER TABLE `TEST_SCHEMA`.`NOT_NULL_TBL` ADD CONSTRAINT `UNIQ_NOT_NULL_TBL` UNIQUE (`INTEGER_UNIQ`); – Changeset /tmp/changelog.xml::1277830437442-7::root (generated)::(Checksum: 2:e8eb13206370d46b46f034c59c3d9dae) ALTER TABLE `TEST_SCHEMA`.`NULL_TBL` ADD CONSTRAINT `UNIQ_NULL_TBL` UNIQUE (`INTEGER_UNIQ`); – Changeset /tmp/changelog.xml::1277830437442-8::root (generated)::(Checksum: 2:985438b9e065cdb8f8939ffb60729f6d) ALTER TABLE `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL` ADD CONSTRAINT `UNIQ_NULL_WITH_DEF` UNIQUE (`INTEGER_UNIQ`); – Changeset /tmp/changelog.xml::1277830437442-9::root (generated)::(Checksum: 2:11d0cfe20bd704c97b75372003a9ae64) ALTER TABLE `TEST_SCHEMA`.`SMALL_TBL` ADD CONSTRAINT `UNIQ_SMALL_TBL_1` UNIQUE (`INTEGER_UNIQ`); – Changeset /tmp/changelog.xml::1277830437442-10::root (generated)::(Checksum: 2:f44ee04280a0c1625a03b0dca3412b82) ALTER TABLE `TEST_SCHEMA`.`NULL_TBL` ADD CONSTRAINT `FK_0001` FOREIGN KEY (`INTEGER_UNIQ`) REFERENCES `TEST_SCHEMA`.`NOT_NULL_TBL`(`INTEGER_UNIQ`) ON UPDATE NO ACTION ON DELETE NO ACTION; – Changeset /tmp/changelog.xml::1277830437442-11::root (generated)::(Checksum: 2:b57ea876519889039c55be27937abea0) ALTER TABLE `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL` ADD CONSTRAINT `FK_0002` FOREIGN KEY (`INTEGER_UNIQ`) REFERENCES `TEST_SCHEMA`.`NOT_NULL_TBL`(`INTEGER_UNIQ`) ON UPDATE NO ACTION ON DELETE NO ACTION; – Changeset /tmp/changelog.xml::1277830437442-12::root (generated)::(Checksum: 2:98c847005ee3cb97df4794bd5c8e62ad) CREATE INDEX `TEST_INDEX2` ON `TEST_SCHEMA`.`NOT_NULL_TBL`(`INTEGER_`); – Changeset /tmp/changelog.xml::1277830437442-13::root (generated)::(Checksum: 2:a9d02d3d239ee49d27f58001820e1710) CREATE INDEX `TEST_INDEX1` ON `TEST_SCHEMA`.`NULL_TBL`(`INTEGER_`); – Changeset /tmp/changelog.xml::1277830437442-14::root (generated)::(Checksum: 2:8dfc4e1891c8ebeb90a8c7eecaf34040) CREATE UNIQUE INDEX `TEST_INDEX3` ON `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL`(`BIGINT_`, `TIME_`); – Changeset /tmp/changelog.xml::1277830437442-15::root (generated)::(Checksum: 2:920c8ab469db1bd68adc8ab5c1f0bf45) CREATE VIEW `TEST_SCHEMA`.`NULL_AND_NOT_NULL` AS SELECT TEST\_SCHEMA.NULL\_TBL.INTEGER\_PK AS INTEGER\_PK,TEST\_SCHEMA.NULL\_TBL.BIGINT\_ AS BIGINT\_,TEST\_SCHEMA.NULL\_TBL.BLOB\_1MB AS BLOB\_1MB,TEST\_SCHEMA.NULL\_TBL.CHAR\_1 AS CHAR\_1,TEST\_SCHEMA.NULL\_TBL.CLOB\_1MB AS CLOB\_1MB,TEST\_SCHEMA.NULL\_TBL.DATE\_ AS DATE\_,TEST\_SCHEMA.NULL\_TBL.DECIMAL\_5\_0 AS DECIMAL\_5\_0,TEST\_SCHEMA.NULL\_TBL.DOUBLE\_ AS DOUBLE\_,TEST\_SCHEMA.NULL\_TBL.INTEGER\_ AS INTEGER\_,TEST\_SCHEMA.NULL\_TBL.REAL\_ AS REAL\_,TEST\_SCHEMA.NULL\_TBL.SMALLINT\_ AS SMALLINT\_,TEST\_SCHEMA.NULL\_TBL.TIME\_ AS TIME\_,TEST\_SCHEMA.NULL\_TBL.TIMESTAMP\_ AS TIMESTAMP\_,TEST\_SCHEMA.NULL\_TBL.VARCHAR\_50 AS VARCHAR\_50 FROM TEST\_SCHEMA.NULL\_TBL UNION ALL SELECT TEST\_SCHEMA.NOT\_NULL\_TBL.INTEGER\_PK AS INTEGER\_PK,TEST\_SCHEMA.NOT\_NULL\_TBL.BIGINT\_ AS BIGINT\_,TEST\_SCHEMA.NOT\_NULL\_TBL.BLOB\_1MB AS BLOB\_1MB,TEST\_SCHEMA.NOT\_NULL\_TBL.CHAR\_1 AS CHAR\_1,TEST\_SCHEMA.NOT\_NULL\_TBL.CLOB\_1MB AS CLOB\_1MB,TEST\_SCHEMA.NOT\_NULL\_TBL.DATE\_ AS DATE\_,TEST\_SCHEMA.NOT\_NULL\_TBL.DECIMAL\_5\_0 AS DECIMAL\_5\_0,TEST\_SCHEMA.NOT\_NULL\_TBL.DOUBLE\_ AS DOUBLE\_,TEST\_SCHEMA.NOT\_NULL\_TBL.INTEGER\_ AS INTEGER\_,TEST\_SCHEMA.NOT\_NULL\_TBL.REAL\_ AS REAL\_,TEST\_SCHEMA.NOT\_NULL\_TBL.SMALLINT\_ AS SMALLINT\_,TEST\_SCHEMA.NOT\_NULL\_TBL.TIME\_ AS TIME\_,TEST\_SCHEMA.NOT\_NULL\_TBL.TIMESTAMP\_ AS TIMESTAMP\_,TEST\_SCHEMA.NOT\_NULL\_TBL.VARCHAR\_50 AS VARCHAR\_50 FROM TEST\_SCHEMA.NOT\_NULL\_TBL; and here is the original version that I made by hand, which does create the foreign keys properly: -- Changeset /tmp/test\_schema.xml::1111111111111-1::root (generated)::(Checksum: 2:056bc56736addda50c7121219bf901ec) CREATE TABLE `TEST_SCHEMA`.`NOT_NULL_TBL` ( `INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_ID` INT NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `BIGINT_` BIGINT NOT NULL, `BLOB_1MB` BLOB NOT NULL, `CHAR_1` CHAR(1) NOT NULL, `CLOB_1MB` TEXT NOT NULL, `DATE_` DATE NOT NULL, `DECIMAL_5_0` DECIMAL(5,0) NOT NULL, `DOUBLE_` DOUBLE NOT NULL, `INTEGER_` INT NOT NULL, `REAL_` REAL NOT NULL, `SMALLINT_` SMALLINT NOT NULL, `TIME_` TIME NOT NULL, `TIMESTAMP_` DATETIME NOT NULL, `VARCHAR_50` VARCHAR(50) NOT NULL, CONSTRAINT `PK_NOT_NULL_TBL` PRIMARY KEY (`INTEGER_PK`), CONSTRAINT `UNIQ_NOT_NULL_TBL` UNIQUE (`INTEGER_UNIQ`) ) ENGINE=INNODB; – Changeset /tmp/test\_schema.xml::1111111111111-2::root (generated)::(Checksum: 2:7c78a789bd7f3a4da25fc7d0cb14f8a3) CREATE TABLE `TEST_SCHEMA`.`NULL_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_ID` INT NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `BIGINT_` BIGINT, `BLOB_1MB` BLOB, `CHAR_1` CHAR(1), `CLOB_1MB` TEXT, `DATE_` DATE, `DECIMAL_5_0` DECIMAL(5,0), `DOUBLE_` DOUBLE, `INTEGER_` INT, `REAL_` REAL, `SMALLINT_` SMALLINT, `TIME_` TIME, `TIMESTAMP_` DATETIME, `VARCHAR_50` VARCHAR(50), CONSTRAINT `PK_NULL_TBL` PRIMARY KEY (`INTEGER_PK`), CONSTRAINT `UNIQ_NULL_TBL` UNIQUE (`INTEGER_UNIQ`) ) ENGINE=INNODB; – Changeset /tmp/test\_schema.xml::1111111111111-3::root (generated)::(Checksum: 2:e93f42f53eda2dfa1f80084e0744837a) CREATE TABLE `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_ID` INT NOT NULL, `INTEGER_UNIQ` INT NOT NULL, `BIGINT_` BIGINT DEFAULT 1, `CHAR_1` CHAR(1) DEFAULT ‘a’, `CLOB_1MB` TEXT, `DATE_` DATE DEFAULT ‘2000-01-01’, `DECIMAL_5_5` DECIMAL(5,5) DEFAULT 0, `DOUBLE_` DOUBLE DEFAULT 3.14, `INTEGER_` INT DEFAULT 1, `REAL_` REAL DEFAULT 3.14, `SMALLINT_` SMALLINT DEFAULT 1, `TIME_` TIME DEFAULT ‘01:23:00’, `TIMESTAMP_` DATETIME, `VARCHAR_50` VARCHAR(50) DEFAULT ‘abc123’, CONSTRAINT `PK_NULL_WITH_DEFAU` PRIMARY KEY (`INTEGER_PK`), CONSTRAINT `UNIQ_NULL_WITH_DEF` UNIQUE (`INTEGER_UNIQ`) ) ENGINE=INNODB; – Changeset /tmp/test\_schema.xml::1111111111111-4::root (generated)::(Checksum: 2:e93f42f53eda2dfa1f80084e0744837a) CREATE TABLE `TEST_SCHEMA`.`SMALL_TBL` (`INTEGER_PK` INT AUTO\_INCREMENT  NOT NULL, `INTEGER_UNIQ` INTEGER NOT NULL, `INTEGER_` INTEGER, CONSTRAINT `PK_SMALL_TBL` PRIMARY KEY (`INTEGER_PK`), CONSTRAINT `UNIQ_SMALL_TBL_1` UNIQUE (`INTEGER_UNIQ`) ) ENGINE=INNODB; – Changeset /tmp/test\_schema.xml::1111111111111-5::root (generated)::(Checksum: 2:e93f42f53eda2dfa1f80084e0744837a) CREATE TABLE `TEST_SCHEMA`.`SMALL_TBL_NO_PK` ( `INTEGER_` INTEGER NOT NULL ) ENGINE=INNODB; – Changeset /tmp/test\_schema.xml::2222222222222-1::root (generated)::(Checksum: 2:f44ee04280a0c1625a03b0dca3412b82) ALTER TABLE `TEST_SCHEMA`.`NULL_TBL` ADD CONSTRAINT `FK_0001` FOREIGN KEY (`INTEGER_UNIQ`) REFERENCES `NOT_NULL_TBL`(`INTEGER_UNIQ`) ON UPDATE NO ACTION ON DELETE NO ACTION; – Changeset /tmp/test\_schema.xml::2222222222222-2::root (generated)::(Checksum: 2:b57ea876519889039c55be27937abea0) ALTER TABLE `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL` ADD CONSTRAINT `FK_0002` FOREIGN KEY (`INTEGER_UNIQ`) REFERENCES `NOT_NULL_TBL`(`INTEGER_UNIQ`) ON UPDATE NO ACTION ON DELETE NO ACTION; – Changeset /tmp/test\_schema.xml::3333333333333-2::root (generated)::(Checksum: 2:98c847005ee3cb97df4794bd5c8e62ad) CREATE INDEX `TEST_INDEX2` ON `TEST_SCHEMA`.`NOT_NULL_TBL`(`INTEGER_`); – Changeset /tmp/test\_schema.xml::3333333333333-3::root (generated)::(Checksum: 2:a9d02d3d239ee49d27f58001820e1710) CREATE INDEX `TEST_INDEX1` ON `TEST_SCHEMA`.`NULL_TBL`(`INTEGER_`); – Changeset /tmp/test\_schema.xml::3333333333333-4::root (generated)::(Checksum: 2:8dfc4e1891c8ebeb90a8c7eecaf34040) CREATE UNIQUE INDEX `TEST_INDEX3` ON `TEST_SCHEMA`.`NULL_WITH_DEFAULT_TBL`(`BIGINT_`, `TIME_`); – Changeset /tmp/test\_schema.xml::1272576312598-12::root (generated)::(Checksum: 2:f9055660845838c9f76ec207bb78ef28) CREATE VIEW `TEST_SCHEMA`.`NULL_AND_NOT_NULL` AS SELECT INTEGER\_PK, BIGINT\_, BLOB\_1MB, CHAR\_1, CLOB\_1MB, DATE\_, DECIMAL\_5\_0, DOUBLE\_, INTEGER\_, REAL\_, SMALLINT\_, TIME\_, TIMESTAMP\_, VARCHAR\_50 FROM TEST\_SCHEMA.NULL\_TBL UNION ALL SELECT INTEGER\_PK, BIGINT\_, BLOB\_1MB, CHAR\_1, CLOB\_1MB, DATE\_, DECIMAL\_5\_0, DOUBLE\_, INTEGER\_, REAL\_, SMALLINT\_, TIME\_, TIMESTAMP\_, VARCHAR\_50 FROM TEST\_SCHEMA.NOT\_NULL\_TBL; Can anyone see why the first one doesn’t create the FK\_0001 & FK\_0002 foreign keys, but the 2nd one does. I used the following query in MySQL to verify whether the constraints were created properly: select \* from information\_schema.TABLE\_CONSTRAINTS tc where tc.TABLE\_SCHEMA = 'TEST\_SCHEMA'; ---
**Author:** ![cpjust](https://avatars.discourse-cdn.com/v4/letter/c/74df32/32.png) [@cpjust](https://forum.liquibase.org/u/cpjust)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/2 "2010-06-29T20:18:00Z")
Wait, I think I found it. My version has ENGINE=INNODB at the end of each CREATE TABLE statement, but the Liquibase version doesn’t.  When I add ENGINE=INNODB to the Liquibase version, it does create the foreign keys. I’m not sure what ENGINE=INNODB does or why Liquibase doesn’t add it.  Is there a way to make Liquibase add ENGINE=INNODB to all the CREATE TABLE lines for MySQL? ---
**Author:** ![scryan7371](https://avatars.discourse-cdn.com/v4/letter/s/87869e/32.png) [@scryan7371](https://forum.liquibase.org/u/scryan7371)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/3 "2010-06-29T20:18:00Z")
Innodb is one of the mysql engines that provides transactional support.  The default does not which is why the foreign keys did not get created.  You can also set your default table type to innodb in the my.cnf file so that all tables you create in that mysql instance will be innodb unless you specify otherwise.  In case you create tables some other way this insures you always get transactional tables by default.  The other default engine is useful when you don’t need transactional integrity like reporting etc. ---
**Author:** ![cpjust](https://avatars.discourse-cdn.com/v4/letter/c/74df32/32.png) [@cpjust](https://forum.liquibase.org/u/cpjust)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/4 "2010-06-29T20:18:00Z")
Thanks. Setting the default in my.cnf works. I wish MySQL would give me an error if I try to add a foreign key with the default MyISAM engine, so I’d know if my constraints got created properly or not.  :(  Otherwise people that use my program would have to remember to always change their my.cnf file manually (since they won’t get any SQL errors if they use foreign keys, but they just won’t get added). I also tried the tag from here:  [http://www.liquibase.org/manual/modify\_sql](http://www.liquibase.org/manual/modify_sql) but it throws this exception: java.sql.SQLException: Can't create table './TEST\_SCHEMA/#sql-61b6\_28.frm' (errno: 150) ---
**Author:** ![cpjust](https://avatars.discourse-cdn.com/v4/letter/c/74df32/32.png) [@cpjust](https://forum.liquibase.org/u/cpjust)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/5 "2010-06-29T20:18:00Z")
Is there a way to get Liquibase to print out the exact SQL commands it’s sending to MySQL when it’s trying to apply a changelog to the database? I’d like to see how the SQL gets affected by adding this to the XML:                 ---
**Author:** ![nvoxland](https://avatars.discourse-cdn.com/v4/letter/n/87869e/32.png) [@nvoxland](https://forum.liquibase.org/u/nvoxland)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/6 "2010-06-29T20:18:00Z")
You can run updateSql instead of update and it will output an update script without modifying the database. You may get info if you set logLevel=TRACE as well Nathan ---
**Author:** ![cpjust](https://avatars.discourse-cdn.com/v4/letter/c/74df32/32.png) [@cpjust](https://forum.liquibase.org/u/cpjust)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/7 "2010-06-29T20:18:00Z")
Do you think it would be appropriate for a future version of Liquibase to automatically add:                 to the tags of tables that use or are referenced by foreign keys in the changelog produced after running a Diff? If it doesn't do that, and MySQL isn't set to use InnoDB by default, then the Foreign Keys will not be added. ---
**Author:** ![nvoxland](https://avatars.discourse-cdn.com/v4/letter/n/87869e/32.png) [@nvoxland](https://forum.liquibase.org/u/nvoxland)\ **Post date:** [June 29, 2010, 8:18pm UTC](https://forum.liquibase.org/t/i-cant-get-foreign-keys-to-work-in-mysql/1412/8 "2010-06-29T20:18:00Z")
It’s not something I would want to add by default, but it would make a great extension ([http://liquibase.org/extensions). ](http://liquibase.org/extensions).%C2%A0) Especially as mysql works to support more engines than just innodb and myisam  I wouldn’t want to force innodb if they explicitly have a different default set. Nathan