merge two tables from different schemas along with updated foreign keys - mysql

Question

I want to merge two tables with same structure from two different schemas. Right now I am doing this through following query:
INSERT INTO schema1.table1(col1,col2)
SELECT col1,col2
FROM schema2.table1;
This query merges two tables fine into one but foreign keys are not updated. They are the same as in original table. So is there any way to do it.
CREATE TABLE `research_delta`.`source` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`url` varchar(500) COLLATE utf8_bin NOT NULL,
`createdOn` datetime NOT NULL,
`modifiedOn` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`isDeleted` tinyint(4) NOT NULL DEFAULT '0',
`structure` mediumblob,
`firstRunStatus` varchar(50) COLLATE utf8_bin NOT NULL DEFAULT '0',
`isMaster` tinyint(4) DEFAULT '0',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='All the sources supported by the system';
CREATE TABLE `research_delta`.`sourcetagitem` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`source` bigint(20) DEFAULT NULL,
`tagItem` bigint(20) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `fk_source_sourcetagitem` (`source`),
KEY `fk_tagItem_sourcetagitem` (`tagItem`),
CONSTRAINT `fk_source_sourcetagitem` FOREIGN KEY (`source`) REFERENCES `source` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `fk_tagItem_sourcetagitem` FOREIGN KEY (`tagItem`) REFERENCES `tagitem` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=287 DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
CREATE TABLE `research_delta`.`tagitem` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(100) COLLATE utf8_bin NOT NULL,
`description` varchar(1000) COLLATE utf8_bin DEFAULT NULL COMMENT 'this field will contain any description details about the type of category or tag..',
`parentId` bigint(20) DEFAULT NULL COMMENT 'if the category or tag in subject to be under any other catefory or tag then this field will contain the id of the category that it is under.',
`createdOn` datetime DEFAULT NULL,
`modifiedOn` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`isDeleted` tinyint(4) NOT NULL DEFAULT '0',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=286 DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='this table represents the tags and categories supported by a';
When i merge two tagitem table from different schema and then merge sourcetagitem table the foreign key i.e tagitem should be updated with updated tagitem id after merging.
Thanks,

Answer 1

Do actually need to merge them, or can you use a union when you want to query the data?
(SELECT * FROM schema1.table1) UNION (SELECT * FROM schema2.table1)
Or create a view in the same way...
CREATE VIEW view1 AS (SELECT * FROM schema1.table1) UNION (SELECT * FROM schema2.table1);
Then select whatever you're interested in from that
SELECT col1 FROM vv;