Error Foreign Key Constraint Failed
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Foreign Key Constraint Failed (code 787)
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A Foreign Key Constraint Fails Mysql Insert
Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up sqlite3 “foreign key constraint failed” up vote 1 cannot add or update a child row a foreign key constraint fails down vote favorite I've set up two tables: create table A(id integer not null primary key autoincrement, name text); create table B(id integer not null primary key autoincrement, id2 integer, book text, foreign key(id2) references A(id)); After I insert data into A, it looks like this: 1 John 2 Amy 3 Peter After I insert data into B, it looks like this: 1 1 Lord of the cannot delete or update a parent row a foreign key constraint fails Rings 2 1 Catch 22 3 2 Sum of All Fears 4 3 Hunt for Red October I then execute the following statement: delete from a where id=1; I get the following: "Error: foreign key constraint failed" I then restart sqlite3 and try again but this time I enter this first: PRAGMA foreign_keys = 1; it still doesn't work...... sqlite sqlite3 foreign-keys share|improve this question edited May 10 at 15:04 tijko 2,35562141 asked Mar 15 '13 at 23:52 A B 51229 add a comment| 3 Answers 3 active oldest votes up vote 5 down vote Table B has rows whose foreign key references the primary key value of the Table A row you are trying to delete so deleting it would violate the integrity of your database. You could include ON DELETE CASCADE in your foreign key definition. With that, when you delete an entry from Table A, any entries in Table B linked to the deleted row would also be deleted. Don't know if that's appropriate for your application. share|improve this answer edited May 10 at 15:01 tijko 2,35562141 answered Mar 16 '13 at 16:35 phaworth 611 add a comment| up vote 2 down vote The "problem" is
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Error In Foreign Key Constraint Of Table
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Sqlite Foreign Key Example
Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: http://stackoverflow.com/questions/15443913/sqlite3-foreign-key-constraint-failed Sign up sqlite and 'constraint failed' error while select and insert at the same time up vote 1 down vote favorite I'm working on migration function. It reads data from old table and inserts it into the new one. All that stuff working in background thread with low priority. My steps in pseudo code. sqlite3_prepare_stmt (select statement) sqlite3_prepare_stmt (insert statement) while (sqlite3_step http://stackoverflow.com/questions/5322669/sqlite-and-constraint-failed-error-while-select-and-insert-at-the-same-time (select statement) == SQLITE_ROW) { get data from select row results sqlite3_bind select results to insert statement sqlite3_step (insert statement) sqlite3_reset (insert statement) } sqlite3_reset (select statement) I'm always getting 'constraint failed' error on sqlite3_step (insert statement). Why it's happend and how i could fix that? UPD: As i'm understand that's happend because background thread use db handle opened in main thread. Checking that guess now. UPD2: sqlite> select sql from sqlite_master where tbl_name = 'tiles'; CREATE TABLE tiles('pk' INTEGER PRIMARY KEY, 'data' BLOB, 'x' INTEGER, 'y' INTEGER, 'z' INTEGER, 'importKey' INTEGER) sqlite> select sql from sqlite_master where tbl_name = 'tiles_v2'; CREATE TABLE tiles_v2 (pk int primary key, x int, y int, z int, layer int, data blob, timestamp real) sql sqlite sqlite3 share|improve this question edited Mar 16 '11 at 13:49 asked Mar 16 '11 at 8:27 Evgen Bodunov 1,98211231 Thanks for the update. I edited my answer and added some more useful (I hope) information. –Mike Sherrill 'Cat Recall' Mar 16 '11 at 15:13 add a comment| 1 Answer 1 active oldest votes up vote 4 down vote accepted It pro
for Developers MariaDB Contributor Agreement MariaDB Contributor Agreement FAQs Community Ambassadors Events Past Events and Conferences Sponsor Sponsors List of Donors Blog About MariaDB Sponsors Governance Logos and https://mariadb.org/mariadb-innodb-foreign-key-constraint-errors/ Badges MariaDB Trademark Usage Statistics Service Providers Maintenance Policy Security Policy Download Learn Get Involved Social Media Getting Started for Developers MariaDB Contributor Agreement MariaDB Contributor Agreement FAQs http://dev.mysql.com/doc/en/innodb-foreign-key-constraints.html Community Ambassadors Events Past Events and Conferences Sponsor Sponsors List of Donors Blog HomeGeneralMariaDB: InnoDB foreign key constraint errors MariaDB: InnoDB foreign key constraint errors 2015-08-07 4 Comments Written foreign key by Jan Lindstrom Introduction A foreign key is a field (or collection of fields) in one table that uniquely identifies a row of another table. The table containing the foreign key is called the child table, and the table containing the candidate key is called the referenced or parent table. The purpose of the foreign key is foreign key constraint to identify a particular row of the referenced table. Therefore, it is required that the foreign key is equal to the candidate key in some row of the primary table, or else have no value (the NULL value). This is called a referential integrity constraint between the two tables. Because violations of these constraints can be the source of many database problems, most database management systems provide mechanisms to ensure that every non-null foreign key corresponds to a row of the referenced table. Consider following simple example: create table parent ( id int not null primary key, name char(80) ) engine=innodb; create table child ( id int not null, name char(80), parent_id int, foreign key(parent_id) references parent(id) ) engine=innodb; As far as I know, the following storage engines for MariaDB and/or MySQL support foreign keys: InnoDB (both innodb_plugin and XtraDB) PBXT (https://mariadb.com/kb/en/mariadb/about-pbxt/) SolidDB for MySQL (http://sourceforge.net/projects/soliddb/) ScaleDB (https://mariadb.com/kb/en/mariadb/scaledb/ and http://scaledb.com/pdfs/TechnicalOverview.pdf) MySQL Cluster NDB 7.3 or later (https://dev.mysql.com/doc/refman/5.6/en/mysql-cluster-ndb-innodb-engines.html) MariaDB foreign key syntax is documented at https://mariadb.com/kb/en/mariadb/foreign-keys/ (and MySQL at http://dev.mysql.com/doc/ref
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