Oracle 查询表的字段和字段类型
SELECT t.TABLE_NAME, t.COLUMN_NAME, t1.DATA_TYPE FROM user_col_comments t
INNER JOIN all_tab_cols t1 ON t1.TABLE_NAME = t.table_name AND t1.COLUMN_NAME = t.column_name
WHERE t.table_name = 'table_name'
查询数据库所有表及表内的数据条数
SELECT TABLE_NAME, NUM_ROWS FROM user_tables