[Bug] [connector-jdbc] PostgresCatalog's SELECT_COLUMNS_SQL_TEMPLATE …

…have some issues (apache#6054)

seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/catalog/sqlserver/SqlServerCatalog.java

@@ -54,13 +54,16 @@ public class SqlServerCatalog extends AbstractJdbcCatalog {
                     + "       col.ORDINAL_POSITION AS column_id,\n"
                     + "       col.DATA_TYPE AS type,\n"
                     + "       CASE WHEN col.DATA_TYPE in ('nchar','nvarchar','ntext') THEN col.CHARACTER_MAXIMUM_LENGTH\n"
-                    + "         ELSE col.CHARACTER_OCTET_LENGTH end  AS max_length,\n"
+                    + "            WHEN col.CHARACTER_OCTET_LENGTH IS NOT NULL AND col.CHARACTER_OCTET_LENGTH > 0 THEN col.CHARACTER_OCTET_LENGTH\n"
+                    + "            ELSE scol.max_length end  AS max_length,\n"
                     + "       CASE WHEN col.DATA_TYPE in ('datetime','datetime2','datetimeoffset','date','time','smalldatetime' ) THEN col.DATETIME_PRECISION \n"
                     + "         ELSE col.NUMERIC_PRECISION end AS precision,\n"
                     + "       col.NUMERIC_SCALE AS scale,\n"
                     + "       col.IS_NULLABLE AS is_nullable,\n"
                     + "       col.COLUMN_DEFAULT AS default_value\n"
                     + "FROM INFORMATION_SCHEMA.COLUMNS col\n"
+                    + "     JOIN sys.columns scol  ON OBJECT_ID(col.TABLE_SCHEMA + '.' + col.TABLE_NAME) = scol.object_id \n"
+                    + "         AND col.COLUMN_NAME = scol.name"
                     + "     LEFT JOIN sys.extended_properties prop\n"
                     + "         ON prop.major_id = OBJECT_ID(col.TABLE_SCHEMA + '.' + col.TABLE_NAME)\n"
                     + "         AND prop.minor_id = col.ORDINAL_POSITION\n"