How to resolve Integrity constraint violation: 1062 Duplicate entry on node_access?
140127
Node Access User Reference module tries to grant access twice, creates integrity violation
106311
How do I find duplicate entries in a database table?
133175
error: SELF_REFERENCE_FROM_TRIGGER while updating child records
26856
How do I specify unique constraint for multiple columns in MySQL?
144631
How to bypass node_access when using EntityFieldQuery?
29817
Closed as a duplicate, but the duplicate list is empty?
102382
Cannot add a nested relation or an element column to a table containing a SimpleContent column
90310
Database DML method executes twice in any record has been failed
5407
How to fix "W: Duplicate sources.list entry"?
104745
Insert query on page load, inserts twice?
68103
Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints
104059
Does a duplicate entries in a PATH variable revoke the precedence given by the first entry?
17091
How can I fix MySQL error #1064?
79118
How to avoid multiple insert in PostgreSQL
132308
How to fix insufficient access rights on cross-reference id?
144338
Can I add a unique constraint that ignores existing violations?
2204
What Causes DatabaseTransactionOutOfOrderException and how do I fix this?