sqlite3查询某字段报错

2019年6月9日 284次阅读 来源: leyu

使用sqlite3的时候，遇到个很奇怪的问题，select某字段的时候，报错感觉像是该字段不存在，但是表中确实是有这个字段的。查询其他字段均没有问题，唯独group这个字段
该表是 kafka监控工具KafkaOffsetMonitor-assembly-0.2.0.jar创建的表，表结构如下

sqlite> .schema OFFSETS
CREATE TABLE "OFFSETS" ("id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,"group" VARCHAR(254) NOT NULL,"topic" VARCHAR(254) NOT NULL,"partition" INTEGER NOT NULL,"offset" BIGINT NOT NULL,"log_size" BIGINT NOT NULL,"owner" VARCHAR(254),"timestamp" BIGINT NOT NULL,"creation" BIGINT NOT NULL,"modified" BIGINT NOT NULL);
CREATE INDEX "idx_search" on "OFFSETS" ("group","topic");
CREATE INDEX "idx_time" on "OFFSETS" ("timestamp");
CREATE UNIQUE INDEX "idx_unique" on "OFFSETS" ("group","topic","partition","timestamp");

查询操作如下，select group字段报错：Error: near “group”: syntax error，但是select topic是没问题的。

sqlite> select * from OFFSETS limit 1;
id          group                    topic                    partition   offset      log_size    owner       timestamp      creation       modified     
----------  -----------------------  -----------------------  ----------  ----------  ----------  ----------  -------------  -------------  -------------
5092201     IM_APP_NOTICE_MSG_OLD_1  IM_APP_NOTICE_MSG_TOPIC  0           1021391     1032122                 1483027807567  1471691588963  1471833538219
sqlite> select * from OFFSETS where group='IM_APP_NOTICE_MSG_OLD_1';
Error: near "group": syntax error
sqlite> select * from OFFSETS where topic='IM_APP_NOTICE_MSG_TOPIC' limit 1;
id          group                    topic                    partition   offset      log_size    owner       timestamp      creation       modified     
----------  -----------------------  -----------------------  ----------  ----------  ----------  ----------  -------------  -------------  -------------
5092201     IM_APP_NOTICE_MSG_OLD_1  IM_APP_NOTICE_MSG_TOPIC  0           1021391     1032122                 1483027807567  1471691588963  1471833538219
sqlite> select group from OFFSETS limit 1;
Error: near "group": syntax error
sqlite> select topic from OFFSETS limit 1;
topic                  
-----------------------
IM_APP_NOTICE_MSG_TOPIC

搜索了半天，也没找到相关资料，但是无意在group字段上加引号后，居然不会报错了。╮(╯▽╰)╭

sqlite> select "topic" from OFFSETS limit 1;
topic                  
-----------------------
IM_APP_NOTICE_MSG_TOPIC

遇到第二个问题：
查询某字典时，字段值若太长，出来的结果会被截断。但是select * 查询出来的不会被截断。还好python操作的时候没有这个问题

sqlite> select DISTINCT "group" from OFFSETS ;
group                 
----------------------
IM_APP_NOTICE_MSG_OLD_
IM_APP_NOTICE_MSG_OLD_


>>> import sqlite3
>>> conn = sqlite3.connect('offsetapp.db')
>>> cur = conn.cursor()
>>> cur.execute('select DISTINCT "group" from OFFSETS ;')
<sqlite3.Cursor object at 0x7f508817c190>
>>> cur.fetchall()
[(u'BINSPECT_MSG_SERVICE_1',), (u'IM_APP_NOTICE_MSG_OLD_1',), (u'IM_APP_NOTICE_MSG_OLD_10',), (u'IM_APP_NOTICE_MSG_OLD_2',), (u'IM_APP_NOTICE_MSG_OLD_3',), ]
    原文作者：leyu
    原文地址: https://www.jianshu.com/p/e8d29afa6589
    本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
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