文档解释
23000: integrity_constraint_violation
Error code 23000: integrity_constraint_violation is an error generated by the PostgreSQL database, typically occurring as a result of an operation that violates a database integrity constraint. This error is highly likely to be caused by a bad transaction or query that has been designed and issued to the database server by an application.
Error Description
The PostgreSQL error “integrity_constraint_violation” tells you that PostgreSQL did not allow the request to be performed because it violated one or more of the rules defined by an integrity constraint. For example, this error can be triggered when trying to insert or update data in a column where the value violates a set of predefined rules defined in the integrity constraint.
Common Cases
One of the most common causes of the PostgreSQL “integrity_constraint_violation” error is attempting to insert or update data that does not meet the criteria set by an integrity constraint, such as a unique key or foreign key.
For example, when trying to insert a row of data into a table where the value assigned to the primary key column is already present in the table, PostgreSQL will return this error because of the unique key integrity constraint on that primary key column.
Another common case is attempting to insert values into a foreign key column when one of the records in the referenced table does not exist. In this case, PostgreSQL will return an integrity_constraint_violation error because of the foreign key integrity constraint on that column.
Resolution
The most important first step when troubleshooting the PostgreSQL “integrity_constraint_violation” error is to understand exactly what integrity constraints are being violated. The most reliable way to do this is to examine the relevant system catalog tables, such as pg_constraint, which stores information on all active constraints in the database.
Once you have identified which integrity constraints are being violated, the next step is to fix the data or queries that are causing these violations. This could involve updating existing data to meet the criteria set by the integrity constraint, or designating a DEFAULT value to be used in place of any data violations.
It is also worth noting that the most reliable way to avoid PostgreSQL “integrity_constraint_violation” errors is to check the queries and transactions before they are sent to the database. This is particularly relevant when working with complex queries and complex transactions, which are more likely to result in an integrity violation.
The PostgreSQL “integrity_constraint_violation” error can also be avoided by ensuring that every integrity constraint is created with appropriate redundancy checks, such as unique indices, foreign key indices, and/or unique constraints. This provides extra data validation prior to entering data into a database and therefore reduces the likelihood of an integrity constraint being violated.
In summary, PostgreSQL “integrity_constraint_violation” is an error generated by the PostgreSQL database, typically occurring as a result of an operation that violates a database integrity constraint. To troubleshoot the error, it is important to first identify the integrity constraint that has been violated, and then use this information to fix the data or queries that are causing the violation. Lastly, it is important to always check queries and transactions prior to sending them to the database, and to create appropriate redundancy checks on all integrity constraints.
