Implement RowsColumnTypeDatabaseTypeName

column.go

@@ -35,6 +35,7 @@ func (l *BufferLen) Bind(h api.SQLHSTMT, idx int, ctype api.SQLSMALLINT, buf []b
 // Column provides access to row columns.
 type Column interface {
 	Name() string
+	DatabaseTypeName() string
 	Bind(h api.SQLHSTMT, idx int) (bool, error)
 	Value(h api.SQLHSTMT, idx int) (driver.Value, error)
 }
@@ -121,6 +122,71 @@ func (c *BaseColumn) Name() string {
 	return c.name
 }
 
+func (c *BaseColumn) DatabaseTypeName() string {
+	switch c.SQLType {
+	case api.SQL_CHAR:
+		return "CHAR"
+	case api.SQL_NUMERIC:
+		return "NUMERIC"
+	case api.SQL_DECIMAL:
+		return "DECIMAL"
+	case api.SQL_INTEGER:
+		return "INTEGER"
+	case api.SQL_SMALLINT:
+		return "SMALLINT"
+	case api.SQL_FLOAT:
+		return "FLOAT"
+	case api.SQL_REAL:
+		return "REAL"
+	case api.SQL_DOUBLE:
+		return "DOUBLE"
+	case api.SQL_DATETIME:
+		return "DATETIME"
+	case api.SQL_TIME:
+		return "TIME"
+	case api.SQL_VARCHAR:
+		return "VARCHAR"
+	case api.SQL_TYPE_DATE:
+		return "TYPE_DATE"
+	case api.SQL_TYPE_TIME:
+		return "TYPE_TIME"
+	case api.SQL_TYPE_TIMESTAMP:
+		return "TYPE_TIMESTAMP"
+	case api.SQL_TIMESTAMP:
+		return "TIMESTAMP"
+	case api.SQL_LONGVARCHAR:
+		return "LONGVARCHAR"
+	case api.SQL_BINARY:
+		return "BINARY"
+	case api.SQL_VARBINARY:
+		return "VARBINARY"
+	case api.SQL_LONGVARBINARY:
+		return "LONGVARBINARY"
+	case api.SQL_BIGINT:
+		return "BIGINT"
+	case api.SQL_TINYINT:
+		return "TINYINT"
+	case api.SQL_BIT:
+		return "BIT"
+	case api.SQL_WCHAR:
+		return "WCHAR"
+	case api.SQL_WVARCHAR:
+		return "WVARCHAR"
+	case api.SQL_WLONGVARCHAR:
+		return "WLONGVARCHAR"
+	case api.SQL_GUID:
+		return "GUID"
+	case api.SQL_SIGNED_OFFSET:
+		return "SIGNED_OFFSET"
+	case api.SQL_UNSIGNED_OFFSET:
+		return "UNSIGNED_OFFSET"
+	case api.SQL_UNKNOWN_TYPE:
+		return ""
+	default:
+		return ""
+	}
+}
+
 func (c *BaseColumn) Value(buf []byte) (driver.Value, error) {
 	var p unsafe.Pointer
 	if len(buf) > 0 {

rows.go

@@ -64,3 +64,17 @@ func (r *Rows) NextResultSet() error {
 	}
 	return nil
 }
+
+// Implement RowsColumnTypeDatabaseTypeName interface in order to return column types.
+// https://github.com/golang/go/blob/e22a14b7eb1e4a172d0c20d14a0d2433fdf20e5c/src/database/sql/driver/driver.go#L469-L477
+//
+// From the docs:
+// RowsColumnTypeDatabaseTypeName may be implemented by Rows. It should return the
+// database system type name without the length. Type names should be uppercase.
+// Examples of returned types: "VARCHAR", "NVARCHAR", "VARCHAR2", "CHAR", "TEXT",
+// "DECIMAL", "SMALLINT", "INT", "BIGINT", "BOOL", "[]BIGINT", "JSONB", "XML",
+// "TIMESTAMP".
+func (rs *Rows) ColumnTypeDatabaseTypeName(i int) string {
+	return rs.os.Cols[i].DatabaseTypeName()
+
+}