| Previous | Next |
| DB_E_CANTCANCEL | DB_E_DUPLICATEDATASOURCE |
DB_E_DIALECTNOTSUPPORTED
Meaning
Windows documents DB_E_DIALECTNOTSUPPORTED as “Command dialect is not supported by this provider”. Here, ICommandText receives a command dialect GUID the provider does not support.
Specific conditions that produce the result
- Cause 1: the consumer assumes DBGUID_SQL for a non-SQL provider.
- Cause 2: a provider-specific dialect GUID is used with a different provider.
- Cause 3: the command object exposes text commands but only a narrower set of dialects.
Relevant OLE DB contract
This result must be interpreted against this contract: an OLE DB command moves through explicit states: command definition, properties and parameters are established before optional preparation and execution; dialect, query-tree and optimizer contracts are provider-specific and should be inferred only from reported capabilities.
Evidence to collect before changing the system
When it involves command text, parameter values, object names and query-plan details, record types, lengths, hashes or redacted identifiers instead of secrets or full business data.
- Evidence 1: the requested dialect GUID and provider CLSID.
- Evidence 2: dialects reported or documented by the provider.
- Evidence 3: the command text source and fallback-selection logic.
Corrective actions
- Action 1: choose a dialect explicitly supported by the active provider.
- Action 2: keep provider-specific command text separated by dialect.
- Action 3: avoid silently relabeling text under a different GUID without translating its syntax.
Practical incident
A component passes an MDX dialect GUID to a relational provider because both share the same command wrapper; provider-aware selection prevents it.
Retry and recovery policy
Retry rule: retry after selecting a supported dialect and supplying command text valid for that dialect.
Difference from related HRESULT values
DB_E_ERRORSINCOMMAND means the dialect was accepted but the command failed parsing or validation, while DB_E_DIALECTNOTSUPPORTED rejects the dialect contract itself.
Official Microsoft references
Looking for a different code? Search another status or error code.