[MM-36995] Start using db native JSON datatypes (#17930)

* Start using db native JSON datatypes

* Fix syntax to work on MySQL 5.7.12

vendor/github.com/mattermost/gorp/column.go

@@ -41,6 +41,9 @@ type ColumnMap struct {
 
 	DefaultValue string
 
+	// The column data type. If set it overrides the one converted from the Go type.
+	DataType string
+
 	fieldName  string
 	gotype     reflect.Type
 	isPK       bool
@@ -86,6 +89,12 @@ func (c *ColumnMap) SetMaxSize(size int) *ColumnMap {
 	return c
 }
 
+// SetDataType allows to specify a custom data type for the column.
+func (c *ColumnMap) SetDataType(dataType string) *ColumnMap {
+	c.DataType = dataType
+	return c
+}
+
 // SetDefaultConstraint adds " default 'value'" to the create table statements for this
 // column, if value is not nil. Not used elsewhere
 func (c *ColumnMap) SetDefaultConstraint(value *string) *ColumnMap {

vendor/github.com/mattermost/gorp/table.go

@@ -215,7 +215,12 @@ func (t *TableMap) SqlForCreate(ifNotExists bool) string {
 			if x > 0 {
 				s.WriteString(", ")
 			}
-			stype := dialect.ToSqlType(col.gotype, col.MaxSize, col.isAutoIncr)
+
+			stype := col.DataType
+			if stype == "" {
+				stype = dialect.ToSqlType(col.gotype, col.MaxSize, col.isAutoIncr)
+			}
+
 			s.WriteString(fmt.Sprintf("%s %s", dialect.QuoteField(col.ColumnName), stype))
 
 			if col.isPK || col.isNotNull {