Forum Discussion
The primary key field of the SQLSERVER2016 table is UUID. Variable parameter passing causes a full t
For example, table1 column id is the primary key, varchar(22), ID is prefixed by N by default during parameter passing, resulting in full table scanning;
select *from table1 where id = '346xPbiLLviw4mxAzoMQT9'
select * from table1 where id = N'346xPbiLLviw4mxAzoMQT9'
- You need to check as the N prefix is used for Unicode character data. As UUID is not Unicode, so you can't use the N prefix while passing the UUID parameter.
As you want to do minimal index scanning, you must avoid using the prefix N as a parameter will be a proper UUID and will avoid performance issues by unnecessary conversions. yachaoh001 , the literal N indicate Unicode = NVarChar and your column has the different data type varchar = ASCII. Mixing different data types in a query can cause full table/index scans.
If the primary key field is set to varchar type, how can I avoid index scanning caused by type conversion during value transfer
yachaoh001 , this is an English spoken forum, so please post in English.
And what's the question/issue.
