我感觉应该将
SELECT a.attname AS field, t.typname AS type,a.attnotnull as null, (case when d.contype = 'p' then 'pri' when d.contype = 'u' then 'uni' else '' end) as key ,ic.column_default as default_value,b.description as comment ,coalesce(character_maximum_length, numeric_precision, -1) as length ,numeric_scale as scale FROM pg_attribute a left join pg_class c on a.attrelid = c.oid left join pg_constraint d on d.conrelid = c.oid and a.attnum = d.conkey[1] left join pg_description b ON a.attrelid=b.objoid AND a.attnum = b.objsubid left join pg_type t ON a.atttypid = t.oid left join information_schema.columns ic on ic.column_name = a.attname and ic.table_name = c.relname WHERE c.relname = 'xxxxxxx' and a.attisdropped is false and a.attnum > 0 ORDER BY a.attnum;
改成
SELECT a.attname AS field, t.typname AS type,a.attnotnull as null, (case when d.contype = 'p' then 'pri' when d.contype = 'u' then 'uni' else '' end) as key ,ic.column_default as default_value,b.description as comment ,coalesce(character_maximum_length, numeric_precision, -1) as length ,numeric_scale as scale FROM pg_attribute a left join pg_class c on a.attrelid = c.oid left join pg_constraint d on d.conrelid = c.oid and a.attnum = d.conkey[1] left join pg_description b ON a.attrelid=b.objoid AND a.attnum = b.objsubid left join pg_type t ON a.atttypid = t.oid left join information_schema.columns ic on ic.column_name = a.attname and ic.table_name = c.relname WHERE c.oid = 'xxxxxxx'::regclass and a.attisdropped is false and a.attnum > 0 ORDER BY a.attnum;

正常逻辑表现，应该是按照优先级，返回第一张表的元数据，这和PG的数据查询表现是一致的。
现在问题是 元数据返回了多张表，数据查询返回的是第一张表。select 多表字段 from 第一张表 导致报错。

PR的实现有点问题，search_path多schema设置下，只会返回第一个schema。 如果表出现在第2个schema里，就会查不到。

如果PR主能看到的话，可以尝试下我的实现，加上单测^_^

@iamcc30 see see

我感觉应该将 SELECT a.attname AS field, t.typname AS type,a.attnotnull as null, (case when d.contype = 'p' then 'pri' when d.contype = 'u' then 'uni' else '' end) as key ,ic.column_default as default_value,b.description as comment ,coalesce(character_maximum_length, numeric_precision, -1) as length ,numeric_scale as scale FROM pg_attribute a left join pg_class c on a.attrelid = c.oid left join pg_constraint d on d.conrelid = c.oid and a.attnum = d.conkey[1] left join pg_description b ON a.attrelid=b.objoid AND a.attnum = b.objsubid left join pg_type t ON a.atttypid = t.oid left join information_schema.columns ic on ic.column_name = a.attname and ic.table_name = c.relname WHERE c.relname = 'xxxxxxx' and a.attisdropped is false and a.attnum > 0 ORDER BY a.attnum; 改成 SELECT a.attname AS field, t.typname AS type,a.attnotnull as null, (case when d.contype = 'p' then 'pri' when d.contype = 'u' then 'uni' else '' end) as key ,ic.column_default as default_value,b.description as comment ,coalesce(character_maximum_length, numeric_precision, -1) as length ,numeric_scale as scale FROM pg_attribute a left join pg_class c on a.attrelid = c.oid left join pg_constraint d on d.conrelid = c.oid and a.attnum = d.conkey[1] left join pg_description b ON a.attrelid=b.objoid AND a.attnum = b.objsubid left join pg_type t ON a.atttypid = t.oid left join information_schema.columns ic on ic.column_name = a.attname and ic.table_name = c.relname WHERE c.oid = 'xxxxxxx'::regclass and a.attisdropped is false and a.attnum > 0 ORDER BY a.attnum;

正常逻辑表现，应该是按照优先级，返回第一张表的元数据，这和PG的数据查询表现是一致的。 现在问题是 元数据返回了多张表，数据查询返回的是第一张表。select 多表字段 from 第一张表 导致报错。

我理解的是只会操作当前的scheme，不会有多个scheme一起查询的情况，不知道是否理解有误。

我理解的是只会操作当前的scheme，不会有多个scheme一起查询的情况，不知道是否理解有误。

不是的，现实中，search_path 很可能配置多个schema。 按照兄台之前的改动，永远只会命中当前schema。而实际情况是根据schema 优先级，命中第一个

如果你配置多个search_path=user,public (默认)，表如果在public下，你的实现就会查不到

我明白你的意思了