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pg中replace和translate的用法说明(数据少的中文排序)

 

这篇文章主要介绍了pg中replace和translate的用法说明(数据少的中文排序),具有很好的参考价值,希望对大家有所帮助。一起跟随小编过来看看吧。1.首先创建students表CREATE TABLE students
(
 id integer NOT NULL,
 name character varying(255),
 sex character varying(255),
 class character varying(255),
 “like” character varying(255),
 school character varying(255),
 phone character varying(255)
) 2.插入数据INSERT INTO “public”.”students” (“id”, “name”, “sex”, “class”, “like”, “school”, “phone”)
VALUES (‘1’, ‘大猫’, ‘女’, ‘一年级’, ‘绘画’, ‘第三小学’, ‘2345’);
INSERT INTO “public”.”students” (“id”, “name”, “sex”, “class”, “like”, “school”, “phone”)
VALUES (‘2’, ‘小厌’, ‘男’, ‘三年级’, ‘书法’, ‘第四小学’, ‘2346’);
INSERT INTO “public”.”students” (“id”, “name”, “sex”, “class”, “like”, “school”, “phone”)
VALUES (‘3’, ‘库库’, ‘女’, ‘二年级’, ‘绘画’, ‘第三小学’, ‘2342’);
INSERT INTO “public”.”students” (“id”, “name”, “sex”, “class”, “like”, “school”, “phone”)
VALUES (‘4’, ‘艾琳’, ‘女’, ‘四年级’, ‘书法,钢琴’, ‘第四小学’, ‘2349’); 结果:1select * from students如下图:3.replace 的用法1replace(string text, from text, to text)返回类型:text解释:把字串string里出现地所有子字串from替换成子字串to示例1:1select replace(‘一条黑色的狗’,’黑’,’黑白相间’)结果:一条黑色的狗 变成了 一条黑白相间色的狗如下图:示例2:1update students set name=replace(name,’大猫’,’小猫咪的姐姐’)结果:name为 ‘大猫’的这条数据name=’小猫咪的姐姐’示例3:1select * from students where school=’第四小学’ ORDER BY replace(name,’艾琳’,’1′)结果:4.translate的用法1translate(string text, from text, to text)返回类型:text解释:把在string中包含的任何匹配from中的字符的字符转化为对应的在to中的字符。示例1:1select translate(‘她真是好看’, ‘好看’,’漂亮’)结果:示例2:select * from students where phone like ‘2%’
ORDER BY translate(class, ‘一二三四’,’1234′) 结果:示例3:select * from students where phone like ‘2%’
ORDER BY translate(name, ‘库小厌猫咪艾’,’1234′) 结果结论:有了translate再也不担心中文排序问题了(数据比较少的情况)补充:pg中position、split_part、translate、strpos、length函数我就废话不多说了,大家还是直接看代码吧~select position(‘.’ in ‘1.1.2.10’);
select split_part(‘1.1.2.10′,’.’,length(‘1.1.2.10’) – length(translate(‘1.1.2.10′,’.’,”))+1);
select split_part(‘1.1.2′,’.’,length(‘1.1.2’) – length(translate(‘1.1.2′,’.’,”))+1);
select length(translate(‘1.1.2.10′,’.’,’a’))+1 as num
select translate(‘1.1.2.10′,’.’,”)
select strpos(‘1.1.2.10′,’.’)
select instr(‘1.1.2.10′,’.’,1,3)
select length(‘1.1.2.10’) – length(translate(‘1.1.2.10′,’.’,”))文章

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