DB2常用SQL的写法(持续更新中...)
-- Author: lavasoft
-- Date : 2006-12-14 -- 创建一个自定义单值类型
create distinct type var_newtype as decimal(5,2) with comparisons; -- var_newtype 类型名
-- decimal(5,2) 实际的类型 -- 删除一个自定义单值类型
drop distinct type var_newtype; -- 创建一个自定义结构数据类型
create type my_type as( username varchar(20), department integer, salary decimal(10,2)) not final mode db2sql; -- 修改自定义结构数据类型,我目前还没有发现删除属性的方法. alter type my_type add attribute hiredate date; -- 删除自定义结构数据类型
drop type my_type; -- 获取系统当前日期 select current date from sysibm.sysdummy1; select current time from sysibm.sysdummy1; select current timestamp from sysibm.sysdummy1; --sysibm.sysdummy1表是一个特殊的内存中的表,用它可以发现如上面演示的 DB2 寄存器的值。您也可以使用关键字 VALUES 来对寄存器或表达式求值。 VALUES current date; VALUES current time; VALUES current timestamp; -- VALUES的更多用法
VALUES 2+5;
VALUES 'hello lavasoft!';
values 56
union all values 45; values 1,2,3,4,5,6
union all values 7,8,9,10,11,12 order by 1; -- 更多变态级DB2 SQL写法,AnyOneTable表示任意一个存在的表
select 234 from AnyOneTable;
select distinct 234 from AnyOneTable; select distinct 234 as 1 from AnyOneTable; select 'DB2变态级的SQL哈哈' from AnyOneTable;
select distinct 'DB2变态级的SQL哈哈' from AnyOneTable; select distinct 'DB2变态级的SQL哈哈' as 1 from AnyOneTable; --(嘿嘿,好玩吧,你可以用任意一个表来当sysibm.sysdummy1用.不过不推荐这么做,除非你不记得sysibm.sysdummy1怎么写了,Oracle中(对应dual)也一样!哈哈哈哈!)
-- 定义变量,还可以设定默认值,给变量赋值
declare var1 char(2); declare var2 int default 0; set var1 = 'aa';
set var2 =23; --创建一个动态游标变量
declare d_cur integer; -- 给变量赋值的另一种方法
values expr1, expr2, expr3 into a, b, c; -- 相当于 set a = expr1; set b = expr2; set c = expr3; -- 还有一种赋值方式
set prodname = (case
when (name is not null) then name when (namestr is not null) then namestr else defaultname end); -- 相当于 set prodname = coalesce(name, namestr, defaultname); --这个类似oracle的decode()和nvl()函数的合并. -- 定义一个游标 declare cur1 cursor with return to client for select * from dm_hy; declare cur2 cursor for select * from dm_hy; -- 静态游标 -- 创建数据表,并添加注释,插入数据. CREATE TABLE tbr_catalog ( id bigint not null generated by default as identity, type smallint not null, name varchar(255), parentid bigint, cataloglevel bigint, description varchar(255), PRIMARY KEY (id) ); comment on table tbr_catalog is 'Birt报表目录表'; comment on column tbr_catalog.ID is '标识'; comment on column tbr_catalog.type is '目录类型'; comment on column tbr_catalog.name is '目录名称'; comment on column tbr_catalog.parentid is '目录父标识'; comment on column tbr_catalog.cataloglevel is '目录层次'; comment on column tbr_catalog.description is '目录描述'; -- 给数据表插入数据
insert into tbr_catalog(id, type, name, parentid, cataloglevel, description) values (1, 0, '系统报表', 0, 0, ''); insert into tbr_catalog(id, type, name, parentid, cataloglevel, description) values (2, 1, '用户报表', 0, 0, ''); -- 创建外键
alter table tbr_storage add constraint fk_tbr_storage foreign key (catalogid) references tbr_catalog(id); -- 更改表,添加列
alter table aaa add sex varchar(1); -- 更改表,删除列 alter table aaa drop column sex; -- 去掉参数前后的空格
rtrim(dm_hy.mc); -- 定义临时表,通过已有person表来创建 declare global temporary table gbl_temp like person on commit delete rows --提交时删除数据 not logged -- 不在日志中纪录 in usr_tbsp -- 选用表空间 -- 此语句创建一个名为 gbl_temp 的用户临时表。定义此用户临时表 所使用的列的名称和说明与 person 的列的名称和说明完全相同。 -- 创建有两个字段的临时表
-- 定义一个全局临时表tmp_hy declare global temporary table session.tmp_hy ( dm varchar(10), mc varchar(10) ) with replace -- 如果存在此临时表,则替换 not logged; -- 不在日志里纪录 -- 给临时表插入三条数据
insert into session.tmp_hy values('1','1'); insert into session.tmp_hy values('1','1'); insert into session.tmp_hy values('1','1'); -- 通过查询批量插入数据
inster into tab_bk(select code,name from table book);
-- select ... into的用法
select * into :h1, :h2, :h3, :h4
from emp where empno = '528671'; -- 语句的流程控制
if() then
open cur1 fetch cur1 into t_equipid; while(at_end<>1)do ...... set t_temp=0; end while; close cur1; else ...... end if; -- 外连接 select empno,deptname,projname
from (emplyoee left outer join project on respemp=empon) left outer join department on mgrno=empno; -- in、like、order by(... ASC|DESC)的用法
select * from book t where t.name like '%J_编程%' and t.code in('J565333','J565222'); order by t.name asc
-- 汇总表(概念复杂,难以理解,不常用)
create summary table sumy_stable1 as (select workdept, count(*) as reccount, sum(salary) as salary, sum(bonus) as bonus from employee group by workdept) data initially deferred refresh immediate; -- 使用SQL一次处理一个集合语义
-- (优化前) select语句中每行的过程层和数据流层之间都有一个上下文切换 declare cur1 cursor for col1,col2 from tab_comp; open cur1; fetch cur1 into v1,v2; while SQLCODE<> 100 do if (v1>20) then insert into tab_sel values(20,v1); else insert into tab_sel values(v1,v2); end if; fetch cur1 into v1,v2; end while; -- (优化后)没有过程层和数据流层之间的上下文切换
declare cur1 cursor for col1,col2 from tab_comp; open cur1; fetch cur1 into v1,v2; while SQLCODE<> 100 do insert into tab_sel(select (case when col1>20 then 20 else col1 end), col2 from tab_comp); fetch cur1 into v1,v2; end while; -- DB2函数分三类:列函数、标量函数、表函数
-- 列函数输入一组数据,输出单一结果。 -- 标量函数接收一个值,返回另外一个值。 -- 表函数只能用于SQL语句的from字句中,它返回一个表的列,类似于一个已创建的常规表。 -- 下面是个标量函数的例子。 create function (salary int,bonus_percent int) returns int language SQL contains SQL return( salary * bonus_percent/100 ) -- 下面是表函数 create function get_marks(begin_range int,end_range int) returns table(cid candidate_id, number test_id, score score) language SQL reads SQL DATA return select cid,number,score from test_taken where salary between (begin_range) and score(end_range) example 1: define a scalar function that returns the tangent of a value using the existing sine and cosine functions.
create function tan (x double)
returns double language sql contains sql no external action deterministic return sin(x)/cos(x) example 2: define a transform function for the structured type person.
create function fromperson (p person) returns row (name varchar(10), firstname varchar(10)) language sql contains sql no external action deterministic return values (p..name, p..firstname) example 3: define a table function that returns the employees in a specified department number.
create function deptemployees (deptno char(3)) returns table (empno char(6), lastname varchar(15), firstname varchar(12)) language sql reads sql data no external action deterministic return select empno, lastname, firstnme from employee where employee.workdept = deptemployees.deptno example 4: define a scalar function that reverses a string.
create function reverse(instr varchar(4000))
returns varchar(4000) deterministic no external action contains sql begin atomic declare revstr, reststr varchar(4000) default ''; declare len int; if instr is null then return null; end if; set (reststr, len) = (instr, length(instr)); while len > 0 do set (revstr, reststr, len) = (substr(reststr, 1, 1) concat revstr, substr(reststr, 2, len - 1), len - 1); end while; return revstr; end example 4: define the table function from example 4 with auditing.
create function deptemployees (deptno char(3))
returns table (empno char(6), lastname varchar(15), firstname varchar(12)) language sql modifies sql data no external action deterministic begin atomic insert into audit values (user, 'table: employee prd: deptno = ' concat deptno); return select empno, lastname, firstnme from employee where employee.workdept = deptemployees.deptno end -- for循环语句的用法
begin atomic
declare fullname char(40); for vl as select firstnme, midinit, lastname from employee do set fullname = lastname concat ',' concat firstnme concat ' ' concat midinit; insert into tnames values (fullname); end for end -- leave的用法
create procedure leave_loop(out counter integer)
language sql begin declare v_counter integer; declare v_firstnme varchar(12); declare v_midinit char(1); declare v_lastname varchar(15); declare at_end smallint default 0; declare not_found condition for sqlstate '02000'; declare c1 cursor for select firstnme, midinit, lastname from employee; declare continue handler for not_found set at_end = 1; set v_counter = 0; open c1; fetch_loop: loop fetch c1 into v_firstnme, v_midinit, v_lastname; if at_end <> 0 then leave fetch_loop; end if; set v_counter = v_counter + 1; end loop fetch_loop; set counter = v_counter; close c1; end -- if语句的用法
create procedure update_salary_if
(in employee_number char(6), inout rating smallint) language sql begin declare not_found condition for sqlstate '02000'; declare exit handler for not_found set rating = -1; if rating = 1 then update employee set salary = salary * 1.10, bonus = 1000 where empno = employee_number; elseif rating = 2 then update employee set salary = salary * 1.05, bonus = 500 where empno = employee_number; else update employee set salary = salary * 1.03, bonus = 0 where empno = employee_number; end if; end -- loop的用法
create procedure loop_until_space(out counter integer)
language sql begin declare v_counter integer default 0; declare v_firstnme varchar(12); declare v_midinit char(1); declare v_lastname varchar(15); declare c1 cursor for select firstnme, midinit, lastname from employee; declare continue handler for not found set counter = -1; open c1; fetch_loop: loop fetch c1 into v_firstnme, v_midinit, v_lastname; if v_midinit = ' ' then leave fetch_loop; end if; set v_counter = v_counter + 1; end loop fetch_loop; set counter = v_counter; close c1; end -- return的用法
begin
... goto fail ... success: return 0 fail: return -200 end -- set变量 的用法
set new_var.salary = 10000, new_var.comm = new_var.salary;
or: set (new_var.salary, new_var.comm) = (10000, new_var.salary); set (new_var.salary, new_var.comm)
= (select avg(salary), avg(comm) from employee e where e.workdept = new_var.workdept); -- whenever的用法
exec sql whenever sqlerror goto handlerr;
exec sql whenever sqlwarning continue; exec sql whenever not found go to enddata; -- while的用法
create procedure dept_median
(in deptnumber smallint, out mediansalary double) language sql begin declare v_numrecords integer default 1; declare v_counter integer default 0; declare c1 cursor for select cast(salary as double) from staff where dept = deptnumber order by salary; declare exit handler for not found set mediansalary = 6666; set mediansalary = 0; select count(*) into v_numrecords from staff where dept = deptnumber; open c1; while v_counter < (v_numrecords / 2 + 1) do fetch c1 into mediansalary; set v_counter = v_counter + 1; end while; close c1; end -- set schema的用法
set schema rick
-- DB2保留关键字
add deterministic leave restart after disallow left restrict alias disconnect like result all distinct linktype result_set_locator allocate do local return allow double locale returns alter drop locator revoke and dsnhattr locators right any dssize lock rollback application dynamic lockmax routine as each locksize row associate editproc long rows asutime else loop rrn audit elseif maxvalue run authorization encoding microsecond savepoint aux end microseconds schema auxiliary end-exec minute scratchpad before end-exec1 minutes second begin erase minvalue seconds between escape mode secqty binary except modifies security bufferpool exception month select by excluding months sensitive cache execute new set call exists new_table signal called exit no simple capture external nocache some cardinality fenced nocycle source cascaded fetch nodename specific case fieldproc nodenumber sql cast file nomaxvalue sqlid ccsid final nominvalue standard char for noorder start character foreign not static check free null stay close from nulls stogroup cluster full numparts stores collection function obid style collid general of subpages column generated old substring comment get old_table synonym commit global on sysfun concat go open sysibm condition goto optimization sysproc connect grant optimize system connection graphic option table constraint group or tablespace contains handler order then continue having out to count hold outer transaction count_big hour overriding trigger create hours package trim cross identity parameter type current if part undo current_date immediate partition union current_lc_ctype in path unique current_path including piecesize until current_server increment plan update current_time index position usage current_timestamp indicator precision user current_timezone inherit prepare using current_user inner primary validproc cursor inout priqty values cycle insensitive privileges variable data insert procedure variant database integrity program vcat day into psid view days is queryno volumes db2general isobid read when db2genrl isolation reads where db2sql iterate recovery while dbinfo jar references with declare java referencing wlm default join release write defaults key rename year definition label repeat years delete language reset descriptor lc_ctype resignal -- SQL99关键字
absolute describe module session action destroy names session_user admin destructor national sets aggregate diagnostics natural size are dictionary nchar smallint array domain nclob space asc equals next specifictype assertion every none sqlexception at exec numeric sqlstate bit false object sqlwarning blob first off state boolean float only statement both found operation structure breadth grouping ordinality system_user cascade host output temporary catalog ignore pad terminate class initialize parameters than clob initially partial time collate input postfix timestamp collation int prefix timezone_hour completion integer preorder timezone_minute constraints intersect preserve trailing constructor interval prior translation corresponding large public treat cube last real true current_role lateral recursive under date leading ref unknown deallocate less relative unnest dec level role value decimal limit rollup varchar deferrable localtime scope varying deferred localtimestamp scroll whenever depth map search without deref match section work desc modify sequence zone --create type (结构化的)用法
create type dept as
(dept name varchar(20), max_emps int) ref using int mode db2sql create type emp as
(name varchar(32), serialnum int, dept ref(dept), salary decimal(10,2)) mode db2sql create type mgr under emp as
(bonus decimal(10,2)) mode db2sql create type address_t as
(street varchar(30), number char(15), city varchar(30), state varchar(10)) not final mode db2sql method samezip (addr address_t) returns integer language sql deterministic contains sql no external action, method distance (address_t)
returns float language c deterministic parameter style sql no sql no external action create type germany_addr_t under address_t as
(family_name varchar(30)) not final mode db2sql create type us_addr_t under address_t as
(zip varchar(10)) not final mode db2sql create type project as
(proj_name varchar(20), proj_id integer, proj_mgr mgr, proj_lead emp, location addr_t, avail_date date) mode db2sql -- create type mapping的用法
create type mapping my_oracle_date
from local type sysibm.date to server type oracle remote type date create type mapping my_oracle_dec
from local type sysibm.decimal(10,2) to server oracle1 remote type number([10..38],2) create type mapping my_oracle_char
from local type sysibm.varchar() to server oracle1 remote type char() create type mapping my_oracle_dec
to local type sysibm.decimal(10,2) from server oracle2 remote type number(10,2) -- create user mapping的用法
create user mapping for rspalten
server server390 options (remote_authid 'system', remote_password 'manager') create user mapping for marcr
server oracle1 options (remote_password 'nzxczy') -- case的用法
case v_workdept
when'a00' then update department set deptname = 'data access 1'; when 'b01' then update department set deptname = 'data access 2'; else update department set deptname = 'data access 3'; end case case
when v_workdept = 'a00' then update department set deptname = 'data access 1'; when v_workdept = 'b01' then update department set deptname = 'data access 2'; else update department set deptname = 'data access 3'; end case -- create trigger的用法
create trigger new_hired
after insert on employee for each row update company_stats set nbemp = nbemp + 1 create trigger former_emp
after delete on employee for each row update company_stats set nbemp = nbemp - 1 create trigger reorder
after update of on_hand, max_stocked on parts referencing new as n for each row when (n.on_hand < 0.10 * n.max_stocked) begin atomic values(issue_ship_request(n.max_stocked - n.on_hand, n.partno)); end create trigger raise_limit
after update of salary on employee referencing new as n old as o for each row when (n.salary > 1.1 * o.salary) signal sqlstate '75000' set message_text='salary increase>10%' create trigger stock_status
no cascade before update of quote on currentquote referencing new as newquote old as oldquote for each row begin atomic set newquote.status = case when newquote.quote > (select max(quote) from quotehistory where symbol = newquote.symbol and year(quote_timestamp) = year(current date) ) then 'high' when newquote.quote < (select min(quote) from quotehistory where symbol = newquote.symbol and year(quote_timestamp) = year(current date) ) then 'low' when newquote.quote > oldquote.quote then 'rising' when newquote.quote < oldquote.quote then 'dropping' when newquote.quote = oldquote.quote then 'steady' end; end create trigger record_history
after update of quote on currentquote referencing new as newquote for each row begin atomic insert into quotehistory values (newquote.symbol, newquote.quote, current timestamp); end -- create tablespace 的用法
create tablespace payroll
managed by database using (device'/dev/rhdisk6' 10000, device '/dev/rhdisk7' 10000, device '/dev/rhdisk8' 10000) overhead 12.67 transferrate 0.18 create tablespace accounting
managed by system using ('d:\acc_tbsp', 'e:\acc_tbsp', 'f:\acc_tbsp') extentsize 64 prefetchsize 32 create tablespace plans
managed by database using (device '/dev/rhdisk0' 10000, device '/dev/rn1hd01' 40000) on dbpartitionnum (1) using (device '/dev/rhdisk0' 10000, device '/dev/rn3hd03' 40000) on dbpartitionnum (3) using (device '/dev/rhdisk0' 10000, device '/dev/rn5hd05' 40000) on dbpartitionnum (5) -- 带case查询条件语句
select (case b.organtypecode
when 'D' then b.parent when 'S' then b.parent else b.id end), b.name from A_ORGAN b where b.id = 999 |
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