SQL: Exceptions

Symptoms : Incorrect coding may cause cause SQL errors when executing.

Impact : Medium

SQL Exceptions will interrupt user flow, and potentially may cause a lack of functionality and influence application performance. This can have a strong negative impact on overall system value by degrading the performance and reliability of the data.

Expected behavior :

SQL exceptions are unexpected and need to investigated.

Possible causes

Network errors  Priority : Medium

Recommended action :
Query Analyzer provides comprehensive information about the error. Example: Network error code 0x79 occurred while establishing a connection; the connection has been closed. This may have been caused by client or server login timeout expiration. Time spent during login: total 19121 ms, enqueued 0 ms, network writes 0 ms, network reads 0 ms, establishing SSL 19120 ms, network reads during SSL 19120 ms, network writes during SSL 0 ms, secure calls during SSL 0 ms, enqueued during SSL 0 ms, negotiating SSPI 0 ms, network reads during SSPI 0 ms, network writes during SSPI 0 ms, secure calls during SSPI 0 ms, enqueued during SSPI 0 ms, validating login 0 ms, including user-defined login processing 0 ms. [CLIENT: 10.90.133.196]See our recommendations regarding network errors here.

Background

SQL exceptions occur where a query has invalid code that cannot be executed.

Some examples are

  • The DELETE statement conflicted with the REFERENCE constraint …
  • type conversion failed
  • Subquery returned more than 1 value.
  • Incorrect syntax near …
  • query timeout
  • Column ‘….’ is invalid in the select list
  • Invalid column name
  • Statement(s) could not be prepared
  • Network error code 0x79 occurred while establishing a connection; the connection has been closed.