ccDangJianExam/Doc/OpenGauss常用命令.txt

# 查询数据库相应用户dsideal的所有序列
SELECT
	*
FROM
	pg_class
WHERE
	relowner = (SELECT usesysid FROM pg_user WHERE usename = 'dsideal')
	AND relkind = 'S'

# 查询所有表名字，默认schema名字是public
SELECT
	tablename
FROM
	pg_tables
WHERE
	schemaname = 'public'

# 查询已知表名tableName的所有字段的字段名、类型、是否为空、注释
SELECT
	A.attname AS NAME,
	format_type(A.atttypid, A.atttypmod) AS TYPE,
	A.attnotnull AS NOTNULL,
	col_description(A.attrelid, A.attnum) AS COMMENT
FROM
	pg_class AS C,
	pg_attribute AS A
WHERE
	C.relname = 'tableName'
	AND A.attnum > 0
	AND A.attrelid = C.oid

# 需要注意修改一下
mysql:ifnull <--> pgsql:COALESCE