一、有区别的函数及解决方案 以下所示的解决方案中的函数定义在untDataBase单元中TAdoConn类的方法中。
序号 | 简述 | Access语法 | SqlServer语法 | Oracle语法 | DB2语法 | 解决方案 | 01 | 系统时间 | Date() | GETDATE() | SYSDATE | | GetSysTimeStr | 02 | 连接字符串 | & | + | || | + | GetConcatStr | 03 | 截取字符串 | SubString
| SubStr
| SubString | SubString | GetSubStr | 04 | 小写字符串 | LCase | Lower | Lower | Lower | GetLowerStr | 05 | 大写字符串 | UCase | Upper
| Upper
| Upper
| GetUpperStr | 06 | 查找字符串 | InStr
| InStr
| CharIndex
| InStr
| GetFindStr | 07 | 替换空值 | IIF+IsNull | Coalesce
| Nvl | Coalesce | GetNullStr | 08 | 条件取值 | IIF | Case+When+Else | DeCode或Case
| IIF
| GetCaseStr | 09 | 字段类型转换 | Str、var、…. | Convert或cast
| To_Char,To_Number. | GetConvertStr
| GetConvertStr | 10 | 日期字符串
| ‘2004-10-9’
| #2004-10-19#
| ‘2004-10-9’ | | GetDateStr | 11 | 最大值加1
| | | | | GetNextNumStr | 12 | Like语句函数 | Like ‘101* | Like ‘101%’
| Like ‘101%’
| | GetLikeStr | | | | | | | | 二、Access与SQLSERVER部分相同数据库函数及关键字列表
1、 函数
2、 关键字
序号
| 简述 | | 01 | | Like | 02 | 连接 | Join | 03 | 判断空 | Is Null | | | | 三、Access与语句SqlServer的语句语法区别
1、 Inser Into …..Select …From 语句:
在ACCESS中以下语句
Insert INTO
PubSubJectAccCopys(Copy_id,Acc_id,Acc_Pid,Acc_name,acc_short,Acc_Comment,Acc_Pro,acc_type,Sub_id_flag,acc_index) (Select 200201,Acc_id,Acc_Pid,Acc_name,acc_short,Acc_Comment,Acc_Pro,acc_type,Sub_id_flag,acc_index FROM PubSubJectAcc Where PubSubJectAcc.co_type='03')
中后面"(select 200201******.co_Type='03')"中的小括号("(",")")必须去掉才能执行,如下:
Insert INTO
PubSubJectAccCopys(Copy_id,Acc_id,Acc_Pid,Acc_name,acc_short,Acc_Comment,Acc_Pro,acc_type,Sub_id_flag,acc_index) Select 200201,Acc_id,Acc_Pid,Acc_name,acc_short,Acc_Comment,Acc_Pro,acc_type,Sub_id_flag,acc_index FROM PubSubJectAcc Where PubSubJectAcc.co_type='03'
在SQL SERVER 中都可以
2、 Inner Join 语句1
StrSql:='select a.user_id,a.user_opcode,b.copy_name from sysuser a inner join (syscopysuser c inner join syscopys b on c.copy_id=c.copy_id) on a.user_id=c.user_id where
a.user_opcode=''' +EdtUserOpCode.text+''' And copy_name='''+Tmpcopyname +'''';
应该改为
StrSql:='select a.user_id,a.user_opcode,b.copy_name from sysuser a inner join (syscopysuser c inner join syscopys b on c.copy_id=d.copy_id) on a.user_id=c.user_id where
a.user_opcode=''' +EdtUserOpCode.text+''' And copy_name='''+Tmpcopyname +'''';
该行代码的检索条件错误:应该把C.copy_id=C.Copy_id 改为c.copy_id=d.copy_id
注:两种写法都能在SQL-SERVER中运行,但c.copy_id=C.copy_id在ACCESS中不能运行
3、 Inner Join 语句2
StrSql:='select copy_year,copy_name,a.copy_id from SysCopys a inner join SysCopysUser b on a.curcopy_flag=1 and a.copy_id=b.copy_id where b.user_id=' + '''' +TmpPubUserID+ '''';
该为
StrSql:='select copy_year,copy_name,a.copy_id from SysCopys a inner join SysCopysUser b on a.copy_id=b.copy_id where a.curcopy_flag=''1'' and b.user_id=' + '''' +TmpPubUserID+ '''';
注:两种写法都能在SQL-SERVER中运行,但第一种在ACCESS中不能运行
4、 Inner Join语句3
SQl server 中可以执行以下语句
'Select distinct sysoption.opti_id,sysoption.opti_name,sysoption.opti_code,sysroleoption.opti_sort From sysoption inner join sysroleoption ON sysoption.opti_id=sysroleoption.opti_id AND sysroleoption.role_id=:roleid'
但ACCESS中不能,只能
'Select distinct sysoption.opti_id,sysoption.opti_name,sysoption.opti_code,sysroleoption.opti_sort From sysoption inner join sysroleoption ON sysoption.opti_id=sysroleoption.opti_id Where sysroleoption.role_id=:roleid'
5、 Update语句
Sql SerVer 中能执行但Access 中不能
'Update sysuserrole SET sysuserrole.role_sort = (Select sysrole.role_sort FROM sysrole Where sysuserrole.role_id = sysrole.role_id and sysuserrole.user_id='01')'
6、 日期比较
SQL SERVER 中用
StrSql:='select copy_year,Start_month,Cur_month,Start_Flag,Start_date,End_date '
+'From SysCopys '
+'where copy_id='''+LoginCopyID+''' '
+'and start_date<='''+datetostr(LoginDate)+''' '
+'and end_date>='''+datetostr(LoginDate)+'''';
ACCESS中用
StrSql:='select copy_year,Start_month,Cur_month,Start_Flag,Start_date,End_date '
+'From SysCopys '
+'where copy_id='''+LoginCopyID+''' '
+'and start_date<=#'+datetostr(LoginDate)+'# '
+'and end_date>=#'+datetostr(LoginDate)+'#'
参考以上的第10个函数“GetDateStr”
7、 最大数值获取语句
StrSql:='insert into sysRoleOption '
+'select '''+fidRoleId+''' as Role_ID,opti_id,'
+'convert(numeric,opti_id)-(convert(numeric,opti_parentid)*100)+'+ MaxOptiSort
+' as opti_Sort from sysoption where opti_parentid='''
+PCoTypeID(self.trvRoles.Selected.data)^.StrCoTypeID
+''' and opti_bottom=''1'+'''';
改为
StrSql:='insert into sysRoleOption '
+'select '''+fidRoleId+''' as Role_ID,opti_id,'
+'opti_id-opti_parentid*100+'+ MaxOptiSort
+' as opti_sort from sysoption where opti_parentid='''
+PCoTypeID(self.trvRoles.Selected.data)^.StrCoTypeID
+''' and opti_bottom=''1'+''''
注:两种写法都能在SQL-SERVER中运行,但第一种在ACCESS中不能运行
但是考虑会出现Null值以及语句的通用性,可以使用以上的第07个函数“GetNullStr”和第09个函数“GetConvertStr”来完成字符串向数字,空值和0数字的转换:参考GetNextNumStr代码。
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