亲测plsql可用。 mysql: 表名:channel_product 列名:EXCHANGE_CODE DROPPROCEDUREIFEXISTSadd_column_channel_product;CREATEPROCEDUREadd_column_channel_product()BEGINIFNOTEXISTS(SELECT1FROMinformation_schema.columnsWHEREtable_name='channel_product'ANDcolumn_name='EXCHANGE_CODE')THENALTERTABLEchannel_productADDCOL...
IF (v_cnt=0)THENEXECUTEimmediate'ALTER TABLE "ACT"."TEMPPHYSICALOPACCOUNTLIST" ADD "ISDUPLICATEREMOVAL1" NUMBER(1,0) DEFAULT 0';ENDif;END;/DECLAREv_cnt number(10,0);BEGINSELECTcount(1)INTOv_cntFROMdba_tab_columns cWHEREc.owner='ACT'ANDTABLE_NAME='TEMPPHYSICALOPACCOUNTLIST'ANDc.column_...
- 通常情况下, 用UNION替换WHERE子句中的OR将会起到较好的效果. 对索引列使用OR将造成全表扫描. 注意, 以上规则只针对多个索引列有效。 如果有column没有被索引, 查询效率可能会因为你没有选择OR而降低. 在下面的例子中, LOC_ID 和REGION上都建有索引. 高效: SELECT LOC_ID , LOC_DESC , REGION FROM LOC...
selectcount(1)intorow_countfromuser_tab_colswhereupper(table_name)=UPPER('z_student')andupper(column_name)=upper('class'); if row_count=0then execute immediate'alter table z_student add class varchar2 default null'; execute immediate'comment on column z_student.class is ''班级'''; commit...
ALTER TABLE,包含ADD COLUMN、ADD INDEX、DROP COLUMN、DROP INDEX、MODIFY COLUMN、RENAME COLUMN DROP TABLE RENAME TABLE、TRUNCATE TABLE、CREATE INDEX 准备工作 登录待迁移的Oracle数据库,创建用于采集数据的账号并授权。... 开启Oracle归档模式 Oracle数据库的归档模式默认为关闭状态,需将其开启才能进行云备份。
Action Selected Not Selected Results When you enter a daily rate to convert currency A to currency B, the inverse rate of currency B to currency A is automatically calculated and entered in the adjacent column. If either rate is changed, the application automatically recalculates the other rate...
Ensure that a grant like the following is present in the file weblogic.policy, or add it if it is not: grant codeBase "file:${oracle.home}/modules/oracle.pki_${jrf.version}/*" { permission java.security.AllPermission; }; The above grant is provided by default. Note that when securi...
Oracle SQL中,可以使用"WHERE EXISTS"子句来替换"DISTINCT"关键字,以实现相同的功能。具体的替换步骤如下: 1. 原始查询使用DISTINCT关键字来返回唯一的结果集,...
I have found that if I put a code that is not in the list of possible values (such as Z) in sh.sprhold_hldd_code = 'Z', then it will return results. DATA: (columnnames abbreviated) SPRIDEN_ID SPRIDEN_LAST SPRIDEN_FIRST SHRDGMR_SEQ_NO SHRDGMR_PROGRAM sh.sprhold_h...
alter table 表名 add(字段名 number(2)); 2、删除一个字段(一般别这么干) alter table 表明 drop column 字段名; 3、修改表名(一般别用) rename oldtablename to newtablename; 4、修改字段的类型 alter table tablename modify(column varchar2(20)); ...