mysql can
syntax requires that Group By is originally grouped according to a field, and the data queried is the only data presentation in this field.
but the data of other fields is different, and sqlserver cannot merge them after grouping, so of course select * can't.
as to why mysql works, someone else must have optimized it and automatically merged the data after Group By .
how do I determine whether the value of a stored procedure variable is empty? Mainly judge whether the input value of the employee s field is empty. In another table, CMSFIE, I define which fields can be empty and which fields cannot be empty, and then...
php;.net: I don t know what s going on? ...
in sql server database, an insert trigger is set for a table, and a new view is created in the trigger. How to design and write statements? Thank you ...
I am using SSMS2017, this version (perhaps earlier version has) has a function, that is, after the cursor is punctuated to something (variable, field, table name, etc.), the same string nearby will be highlighted, such as figure: " " >> similar func...
the data sent from the front desk is of date type, and then query how to report such an error in the field of date type of sql server database based on this data: ,date : : : ...
Why is typesetting always messy when using SQLserver s sqlcmd to execute select on ubuntu? the following figure shows the effect after sp_help student has been executed. select * from sys.tables is the same ...
what is stored in the database is the html code, which is mainly a piece of div content, including the style, does not contain the body and other tags, and the label is strict in opening and closing. If I want to query the keyword "class " now, if I us...
in the win7 system, install the sql2012 database and pop up to wait for the database engine to recover. Look for the reason on the Internet. You can see the solution with an answer on Zhihu: change the account to start Database engine to NT AuthorityNe...
when writing insert sql statements with python + cx_oracle, the error message is an invalid ORA-01722: number. The field types of the two tables are the same, and they are executed in PL SQL, and the field that reported the error is found. But after loo...
if the picture is a table, how to find the data equal to 8 in the three fields of mobile1 or mobile2 or mobile3 although you can use where or, ask God how to write sql statements if you don t use where or. Ask for advice ...
1. Process: Python looks up the data in the table through cx_Oracle and inserts the data into another table. 2. The type of date and time stored in both tables is of type Date. 3. The time field I took from the query table prints out that the type i...
is there any way? such as recommended books, blogs, etc. ...
1. I want to use EF6 s Code First to create my application, but I have a field type in the database for text type, I would like to ask whether it can only be expressed as String type in Model at this time, if so, should I specify data annotation StringL...
SELECT Table_1. , Table_2. , Table_3.* FROM ((Table_1 INNER JOIN Table_2 ON Table_1.DataTime = Table_2.DataTime) INNER JOIN Table_3 ON Table_2.DataTime = Table_3.DataTime) where Table_1.DataTime = 1 is not necessarily merging three tables with the same ...
the case is that one field of data has many identical items, but other fields have different data. I want to select the same field first and then delete the statement that is different but the data is small, leaving only the largest statement according...
the result returned is empty ! [picture upload.] obviously I have created a field ...
private static string connStr = ConfigurationManager.ConnectionStrings [ "data "] .ConnectionString; what does that mean? I don t understand. I m going to connect to the database and winform . What is [ "data "] copy it from a blogger. ...
the company s product tables currently have 3, and there may be 20 + in the future, and the amount of data varies from tens of thousands to millions, each of which needs to be maintained separately and cannot be merged together. At present, I want to c...
1. Such as the title. 2.laravel reported an error The Response content must be a string or object implementing _ _ toString (), "boolean " given. looked up some information and said that the json_encode illegal character is the binary. 3. Using th...
I want to use the Sqlcommand of C-sharp to execute DROP LOGIN (user) to delete the login account of SQL Server, but it seems that Sqlcommand cannot execute this statement. I can successfully execute it under SQL Server management studio and console. Is ...