sql - Firebird 中的表名有很多额外的空间

Question

所以，我在 Firebird 中创建了一个表，使用 Python fdb 库，如下所示:

>>> import fdb

>>> conn = fdb.connect(...)
>>> sql = "CREATE TABLE test_table(id integer not null)"
>>> cursor = conn.cursor()
>>> cursor.execute(sql)
>>> conn.commit()

但是，当我列出表格时，我得到了这个奇怪的结果:

>>> tables = []
>>> sql = "select rdb$relation_name from rdb$relations 
       where rdb$view_blr is null and (rdb$system_flag is null or rdb$system_flag = 0)"
>>> cursor.execute(sql)
>>> res = cursor.fetchall()
        for r in res:
            tables.append(r[0])
>>> tables
['TEST_TABLE                     ']

到底他妈发生了什么？这个愚蠢的额外空间从何而来？为什么我的表被命名为 "TEST_TABLE "而不仅仅是 "TEST_TABLE" ?

Answer 1

field :

RDB$RELATION_NAME is CHAR(31)

CHAR 用空格填充。

The most important difference is that CHAR is padded with spaces andVARCHAR is not. For example, if you have:

CREATE TABLE t1 ( c1 VARCHAR(2), c2 CHAR(2) );

INSERT INTO t1 (c1,c2) VALUES ('a', 'a');

The column c1 will contain value 'a', while column c2 will containvalue 'a ' with additional space.Trailing spaces are ignored when doing comparisons, so both columns would >match the

WHERE c = 'a'

clause of some query. Trailing spaces are respected by LIKE operator, which >is a source of confusion for beginners

见: http://www.firebirdfaq.org/faq237/