Query basic metadata in a certain mode of Shentong database: table name, table comment, field name, field type, field length
SELECT
a.TABLE_NAME,
a.COLUMN_NAME,
a.DATA_TYPE,
IFNULL(CHAR_MAX_LENGTH,NUM_PREC) AS DATA_LENGTH,
b.COMMENTS AS TABLE_COMMENTS,
c.COMMENTS AS COLUMN_COMMENTS
FROM
(
SELECT
TABLE_NAME,
COLUMN_NAME,
DATA_TYPE,
CHAR_MAX_LENGTH,
CHAR_OCTET_LENGTH,
NUM_PREC
FROM
INFO_SCHEM.COLUMNS
WHERE
-- 选取指定模式下的所有表
TABLE_SCHEM = 'SYSDBA'
) a
LEFT JOIN INFO_SCHEM.ALL_TAB_COMMENTS b ON
a.TABLE_NAME = b.TABLE_NAME
LEFT JOIN INFO_SCHEM.ALL_COL_COMMENTS c ON
c.COLUMN_NAME = a.COLUMN_NAME
AND c.TABLE_NAME = a.TABLE_NAME