如何使用psycopg2在postgres中获取表？

Question

有人能解释一下如何在当前数据库中获取这些表吗？

我使用的是postgresql-8.4 psycopg2。

Answer 1

这为我做了这个把戏：

cursor.execute("""SELECT table_name FROM information_schema.tables
       WHERE table_schema = 'public'""")
for table in cursor.fetchall():
    print(table)

Answer 2

pg_class存储所有必需的信息。

执行以下查询将以列表中的元组形式返回用户定义的表

conn = psycopg2.connect(conn_string)
cursor = conn.cursor()
cursor.execute("select relname from pg_class where relkind='r' and relname !~ '^(pg_|sql_)';")
print cursor.fetchall()

输出：

[('table1',), ('table2',), ('table3',)]

Answer 3

问题是如何使用python的psycopg2来处理postgres。这里有两个方便的函数：

def table_exists(con, table_str):

    exists = False
    try:
        cur = con.cursor()
        cur.execute("select exists(select relname from pg_class where relname='" + table_str + "')")
        exists = cur.fetchone()[0]
        print exists
        cur.close()
    except psycopg2.Error as e:
        print e
    return exists

def get_table_col_names(con, table_str):

    col_names = []
    try:
        cur = con.cursor()
        cur.execute("select * from " + table_str + " LIMIT 0")
        for desc in cur.description:
            col_names.append(desc[0])        
        cur.close()
    except psycopg2.Error as e:
        print e

    return col_names