</isNotNull> 即使你在bean中不设置id的值，id的初始值也是0而不是null;所以这样配置a.id会等于0 而你把name变量用isNotNull这样配置，name如果不设置值，初始就是null,name的条件不就添加在sql中；isEqual相当于equals，数字用得多些，一般都是判断状态值 <isEqual property="state"compareValue="...
isEqual判断是否相等 isNull判断是否为Null值，就是没有传值（连空格都没有传）
Since we didn’t provide a value forSomeAlphaValue, SQL Server shows a NULL in the query results where that column value was expected to be. This NULL indicates the absence of a value. We provided nothing in the insert statement. It’s not the same as an empty string for character data...
There is another expression/function present in all three RDBMS that is used with NULL and that is NULLIF(). This last function has two arguments and returns NULL if both arguments are equal, otherwise it returns the first argument. Let’s review some examples! SQL Server We need to report...
java.sql.SQLIntegrityConstraintViolationException: ORA-00001: unique constraint (USR_JXZX_DSJKF_MODEL.SYS_C001362707) violated 主键不一致,须联系数据中心修改 经DataX智能分析,该任务最可能的错误原因是: com.alibaba.datax.common.exception.DataXException: Code:[Framework-14], Description:[DataX传输脏数据...
已解决: nested exception is java.sql.SQLDataException: ORA-01476: divisor is equal to zero 问题 oracle 除零异常,且sql重复语句过多 思路 使用decode 或者 NULLIF 解决除零异常问题 原SQL case when冗余 可以用 case when in 简化 解决 在这个修改后的SQL语句中,NULLIF函数用于处理zzje、zxjje和jxjje计算...
<=: tests whether the first value is less than or equal to the second >=: tests whether the first value is greater than or equal to the second Null: Predicates that use theIS NULLoperator test whether values in a given column are NullRange: Range predicates use theBETWEENoperator to test...
NULL is a special value in SQL that represents a missing or an unknown value. NULL is used for fields with unknown or inapplicable values. It's different from an empty or zero value. No two NULL values are equal. Any field in a table can be defined to allow (or not allow) NULL val...
oracle除零异常,且sql重复语句过多 思路 使用decode 或者 NULLIF 解决除零异常问题 原SQL case when冗余 可以用 case when in 简化 解决 在这个修改后的SQL语句中,NULLIF函数用于处理zzje、zxjje和jxjje计算中的被零除错误。如果分母为零,则NULLIF函数返回NULL,防止被零除的错误。
intoacolumn,use\Ninthe datafile. The literal word “NULL” may also be used undersomecircumstances. See Section13.2.6, “LOADDATA INFILE Syntax”.WhenusingDISTINCT,GROUPBY,orORDERBY,allNULLvaluesare regardedasequal.WhenusingORDERBY,NULLvaluesare presented first,orlastifyou specifyDESCtosortin...