greenplum（三） gp工具命令及工具函数语句，持续更新.....

1 命令行导入文本数据到表

psql -d bass_gp -h 10.243.4.145 -p 5432 -U dwadm -c "\copy dwtmp.tmp_test(cellid) from /data/22.txt "

bass_gp  是数据库名及database名

10.243.4.145  ip地址

 5432  是端口号

dwadm 账号

2

类似于 oracle wm_concat (列名),该函数可以把列值以","号分隔起来,并显示成一行,接下来上例子,看看这个神奇的函数如何应用

string_agg

"empno"  "ename"  "job"         "mgr"       "hiredate"        "sal"         "comm"   "deptno"

"7499"     "ALLEN"   "SALESMAN"   "7698"     "1981/2/20"    "1600"     "300"        "30"

"7566"     "JONES"   "MANAGER"    "7839"     "1981/4/2"       "2975"     ""          "20"

"7654"     "MARTIN"        "SALESMAN"   "7698"     "1981/9/28"    "1250"     "1400"     "30"

其中7499和7654是同一个deptno的，为30，另外一个7566的deptno为20。

Select deptno,string_agg(ename,',’)ename_agg from emp group by deptno;

结果为：

Deptno ename_agg

20    JONES

30    ALLEN,MARTIN

3 postgresql存储过程使用方法 ，代码结构：

declare
cursor record 
begin

for cursor in
;
loop
enend loop;

4 查询表字段注释语句：

 select a.attname as columnname,
pg_catalog.format_type(a.atttypid, a.atttypmod) as data_type,
decode(a.attnotnull,'t','not null','f',null),COALESCE(b.description,'')  as comment
 from pg_catalog.pg_attribute a
left join pg_catalog.pg_description b on b.objoid=a.attrelid and b.objsubid=a.attnum
where a.attrelid ='dwctr.tc_newuser_10days_gsm_day'::regclass
 and a.attnum > 0
 and not a.attisdropped
 order by a.attnum;