- --dialect <DIALECT>
SQL dialect.
By default the native SQL of an RDBMS is used when using
gdal vector sql
. If usingsql
as a step ofgdal vector pipeline
, this is only true if the step precedingsql
isread
, otherwise the OGRSQL dialect is used.If a datasource does not support SQL natively, the default is to use the
OGRSQL
dialect, which can also be specified with any data source.The SQL SQLite dialect dialect can be chosen with the
SQLITE
andINDIRECT_SQLITE
dialect values, and this can be used with any data source. Overriding the default dialect may be beneficial because the capabilities of the SQL dialects vary. What SQL dialects a driver supports can be checked with "gdal vector info".Supported dialects can be checked with
gdal vector info
. For example:$ gdal vector info --format "PostgreSQL" Supported SQL dialects: NATIVE OGRSQL SQLITE $ gdal vector info --format "ESRI Shapefile" Supported SQL dialects: OGRSQL SQLITE