feat: add extract query builders for both dialects

Add QueryFromObject helpers to build select queries from a table schema, with limits and geometry support.

cmd/go_migrate/mssql-transform.go

@@ -1,52 +0,0 @@
-package main
-
-import (
-	"encoding/binary"
-)
-
-func mssqlUuidToBigEndian(mssqlUuid []byte) []byte {
-	if len(mssqlUuid) != 16 {
-		return mssqlUuid
-	}
-	pgUuid := make([]byte, 16)
-	pgUuid[0], pgUuid[1], pgUuid[2], pgUuid[3] = mssqlUuid[3], mssqlUuid[2], mssqlUuid[1], mssqlUuid[0]
-	pgUuid[4], pgUuid[5] = mssqlUuid[5], mssqlUuid[4]
-	pgUuid[6], pgUuid[7] = mssqlUuid[7], mssqlUuid[6]
-	copy(pgUuid[8:], mssqlUuid[8:])
-
-	return pgUuid
-}
-
-const sridFlag = 0x20000000
-
-func wkbToEwkbWithSrid(geometry []byte, srid int) []byte {
-	if len(geometry) < 5 {
-		return geometry
-	}
-
-	var byteOrder binary.ByteOrder
-	if geometry[0] == 0 {
-		byteOrder = binary.BigEndian
-	} else {
-		byteOrder = binary.LittleEndian
-	}
-
-	wkbType := byteOrder.Uint32(geometry[1:5])
-	if wkbType&sridFlag != 0 {
-		return geometry
-	}
-
-	ewkbType := wkbType | sridFlag
-
-	result := make([]byte, len(geometry)+4)
-
-	result[0] = geometry[0]
-
-	byteOrder.PutUint32(result[1:5], ewkbType)
-
-	byteOrder.PutUint32(result[5:9], uint32(srid))
-
-	copy(result[9:], geometry[5:])
-
-	return result
-}