ORACLE 创建表前判断是否已存在

Posted 2023-06-08 Chr☆s Kwok 的技术笔记

1、判断是否用户数据表已存在，不存在则创建：

DECLARE v_cnt number;
BEGIN
  SELECT count(1) INTO v_cnt FROM dba_tables WHERE owner=\'ACT\' AND TABLE_NAME=\'PHYSICALORDERPRESCRIPTIONMAP\' ;
  IF v_cnt = 0  THEN
    EXECUTE immediate
      \'CREATE TABLE "ACT"."PHYSICALORDERPRESCRIPTIONMAP" 
      (  "PHYSICALREGISTERID" NUMBER(10,0) NOT NULL ENABLE, 
      "PHYSICALREGISTERITEMID" NUMBER(10,0) NOT NULL ENABLE, 
      "ENCOUNTERID" NUMBER(10,0) NOT NULL ENABLE, 
      "ORDERPRESCRIPTIONID" NUMBER(10,0) NOT NULL ENABLE, 
      "AMOUNT" NUMBER(18,4), 
      "ATTACHAMOUNT" NUMBER(18,4), 
      "ISDELETED" NUMBER(1,0) DEFAULT 0, 
      "ROWVERSION" TIMESTAMP (6) DEFAULT systimestamp, 
      "PHYSICALPARTYEXAMLABELID" NUMBER(10,0), 
      "PHYSICALITEMCLASSIFICATIONFLAG" NUMBER(3,0) DEFAULT 0, 
      "COMPOSITEITEMID" NUMBER(10,0), 
      "PHYSICALREGISTERBALANCEID" NUMBER(10,0), 
      "PEREGISTERDATE" DATE, 
      "PESEQNO" NUMBER(10,0), 
      "STATUSCODEID" NUMBER(10,0) DEFAULT (0), 
    CONSTRAINT "PHYSICALORSMAP_PK" PRIMARY KEY ("PHYSICALREGISTERID", "PHYSICALREGISTERITEMID", "ENCOUNTERID", "ORDERPRESCRIPTIONID"))\';
  END if;
end;
/

2、判断是否全局临时表已存在，不存在则创建：

DECLARE v_cnt number;
BEGIN
  SELECT count(1) INTO v_cnt FROM dba_tables WHERE owner=\'ACT\' AND TABLE_NAME=\'TEMPPHYSICALOPACCOUNTLIST\' ;
  IF v_cnt = 0  THEN
    EXECUTE immediate
    \'CREATE GLOBAL TEMPORARY TABLE "ACT"."TEMPPHYSICALOPACCOUNTLIST" 
       (  "ACCOUNTLISTID" NUMBER(10,0), 
      "ORDERPRESCRIPTIONID" NUMBER(10,0), 
      "PARENTORDERPRESCRIPTIONID" NUMBER(10,0), 
      "ENCOUNTERID" NUMBER(10,0), 
      "ACCOUNTINGORGANIZATIONID" NUMBER(10,0), 
      "COSTORGANIZATIONID" NUMBER(10,0), 
      "ACCOUNTINGEMPLOYEEID" NUMBER(10,0), 
      "ACCOUNTINGDATETIME" DATE, 
      "OCCURDATE" DATE, 
      "APPENDDATETIME" DATE, 
      "EXECORGANIZATIONID" NUMBER(10,0), 
      "ACCOUNTINGDOCTORID" NUMBER(10,0), 
      "ORDERSOURCEFLAG" NUMBER(3,0), 
      "MAINCONSUMABLECODEID" NUMBER(10,0), 
      "MAINCONSUMABLEID" NUMBER(10,0), 
      "CONSUMABLECODEID" NUMBER(10,0), 
      "CONSUMABLEID" NUMBER(10,0), 
      "PRICE" NUMBER(18,4), 
      "QUANTITY" NUMBER(18,4), 
      "AMOUNT" NUMBER(18,4), 
      "FEEKINDID" NUMBER(10,0) DEFAULT -1, 
      "PAYPROPORTION" NUMBER(18,4) DEFAULT 10000, 
      "HASPAID" NUMBER(1,0) DEFAULT 0, 
      "ISFEEKINDFROMCALC" NUMBER(1,0) DEFAULT 0, 
      "STANDARDPRICE" NUMBER(18,4), 
      "ISDUPLICATEREMOVAL" NUMBER(1,0) DEFAULT 0, 
      "PHYSICALCLASSIFICATIONFLAG" NUMBER(10,0) DEFAULT 1, 
      "PHYSICALITEMCLASSIFICATIONFLAG" NUMBER(10,0) DEFAULT 0 ) ON COMMIT DELETE ROWS\';
  END if;
end;
/

DECLARE
v_cnt number(10,0);
BEGIN
  SELECT count(1) INTO v_cnt FROM dba_tab_columns c WHERE c.owner=\'ACT\' AND TABLE_NAME=\'TEMPPHYSICALOPACCOUNTLIST\' AND c.column_name = \'ISDUPLICATEREMOVAL1\';
  IF (v_cnt = 0) THEN  
     EXECUTE immediate \'ALTER TABLE "ACT"."TEMPPHYSICALOPACCOUNTLIST" ADD "ISDUPLICATEREMOVAL1" NUMBER(1,0) DEFAULT 0\';
  END if;
END;
/

DECLARE
v_cnt number(10,0);
BEGIN
  SELECT count(1) INTO v_cnt FROM dba_tab_columns c WHERE c.owner=\'ACT\' AND TABLE_NAME=\'TEMPPHYSICALOPACCOUNTLIST\' AND c.column_name = \'PHYSICALCLASSIFICATIONFLAG\';
  IF (v_cnt = 0) THEN  
     EXECUTE immediate \'ALTER TABLE "ACT"."TEMPPHYSICALOPACCOUNTLIST" ADD "PHYSICALCLASSIFICATIONFLAG" NUMBER(10,0) DEFAULT 1\';
  END if;
END;
/

DECLARE
v_cnt number(10,0);
BEGIN
  SELECT count(1) INTO v_cnt FROM dba_tab_columns c WHERE c.owner=\'ACT\' AND TABLE_NAME=\'TEMPPHYSICALOPACCOUNTLIST\' AND c.column_name = \'PHYSICALITEMCLASSIFICATIONFLAG\';
  IF (v_cnt = 0) THEN  
     EXECUTE immediate \'ALTER TABLE "ACT"."TEMPPHYSICALOPACCOUNTLIST" ADD "PHYSICALITEMCLASSIFICATIONFLAG" NUMBER(10,0) DEFAULT 0\';
  END if;
END;
/

 

Oracle SQL示例

创建表：

 1 --删除表：
 2 --创建表前删除已存在的同名表，确保能够创建成功。
 3 --但是这种操作非常危险，万一删除了不该删的表，会非常糟糕。
 4 Drop table T_emp;　
 5 --创建表：　
 6 create table T_emp
 7 (
 8 　　empno number not null,
 9 　　empname varchar(20) not null,
10 　　gender nvarchar(1) not null,
11 　　age number not null,
12 　　createtime date default sysdate,
13 　　isdelete char(1) default(‘N‘) not null,
14 　--创建约束（主键约束，唯一约束，check约束）　
15 　　constraint pk_empno primary key(empno),
16 　　constraint u_empname unique(empname),
17 　　constraint c_isdelete check(isdelete in(‘Y‘,‘N‘)　　
18 );

View Code

插入记录：

 1 /*插入记录*/
 2 
 3 --完整填写
 4 insert into T_emp
 5 (
 6    empno,
 7    empname,
 8    gender,
 9    age.
10    createtime,
11    isdelete    
12 )
13 values
14 (
15    ‘x1234567‘,
16    ‘关云长‘,
17    ‘男‘,
18    ‘24‘,
19    sysdate,
20    ‘N‘
21 );
22 
23 --仅填写两个不可重复的字段
24 insert into T_emp
25 (
26    empno,
27    empname
28 )
29 values
30 (
31    ‘x1234568‘,
32    ‘赵子龙‘
33   );

View Code

删除记录：

1 --删除记录
2 delete from t_emp
3 where empno=‘x1234567‘;

View Code

更新记录：

1 update t_emp
2 set empno=‘x7654321‘
3 where empno=‘x1234567‘;

View Code

查询记录：

1 select empno,empname 
2 from t_emp
3 where rownum<=2;

View Code