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I need to merge several databases, where the destination table has a constraint checking for MULTIPOLYGONM in the geometry column.

At some source tables, the geometry column is in the XY form (MULTIPOLYGON), others have the correct XYM form (MULTIPOLYGONM).

How can I force MULTIPOLYGON into MULTIPOLYGONM? Is this what ST_Force_3DM is supposed to do?

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up vote 1 down vote accepted

Seems like ST_Force_3DM alone is not enough for an "INSERT FROM SELECT", but this worked for me:

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