Common SQL Errors and How to Fix Them
Browse all documented SQL errors with detailed explanations, root causes, and step-by-step fixes.
ERROR: syntax error at or near 'AS' Line 1, column 18
This error occurs when the SQL parser encounters a syntax error at a specific point in the query. In this case, the erro…
Error parsing expression for ORDER BY clause: 'id' does not exist in the query
This error occurs when the SQL framework is unable to parse the ORDER BY clause due to a non-existent column being refer…
SQLSTATE[HY000][2002] Can't connect to local MySQL server through socket '/var/r
This error occurs when the SQL client is unable to connect to the MySQL server. It typically happens when the MySQL serv…
Cannot create index on existing column 'address' because it is used in a CHECK c
This error occurs when you try to create a new index on a column that already exists in the database and is being used t…
SQL Error (1146): Table 'mydb.mycustomer' doesn't exist
This error occurs when the database engine cannot find a specified table in the database. The table may have been delete…
Error executing query: 'SQLSTATE[HY000] [2002] No such file or directory' while
This error occurs when the SQL framework is unable to connect to the database due to a missing or incorrect database fil…
SQLSTATE[HY000][1049] Unknown database 'my_database_name'
This error occurs when the database name provided in the SQL query is unknown or does not exist in the MySQL server's da…
SQLSTATE[HY000] [2002] Connection to MySQL server at 'localhost:3306' failed: un
This error occurs when the MySQL connection fails due to a certificate verification issue. It usually happens when the s…
ORA-12545: Connection count is exceeded
This error occurs when the maximum number of connections to an Oracle database is exceeded. This can happen when too man…
SQLSTATE[HY000] [20006] The MySQL server has gone away
This error occurs when the MySQL server times out due to an idle connection or a large result set, usually because the q…
Unclosed parenthesis in query at or near ','
This error occurs when a developer forgets to close a parenthesis in a SQL query, usually while grouping data or using s…
Invalid connection pool size. Minimum value is 1. The specified value '0' is out
This error occurs when the application attempts to create a connection pool with a size that is less than the minimum al…
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