SQL – SQL Questions Answer

Sync columns(without data) in multiple tables

I have multiple tables inside my database: Is there a way to keep the columns of all the tables in sync with each other? What I mean is that when I add a new column named ‘⁣last-edit’ inside the first table, this column will duplicate to all the other tables. But the data inside the columns will only be unique

Converting a half-hourly data into Quarter-hourly data by taking mean of half-hourly values in SQL?

I have half-hourly (30 min interval) Data Table in SQL (SSMS). I want to convert it to Quarter-hourly (15 min interval) by taking mean/average of the preceding and succeeding values. What SQL query should I run for it? Answer Using cross apply to convert a single row to a pair of rows

Difference between dm_exec_sql_text vs dm_exec_input_buffer

As per Microsoft docs, dm_exec_sql_text returns the text of the SQL batch that is identified by the specified sql_handle while dm_exec_input_buffer returns information about statements submitted to an instance of SQL Server. I used DBCC INPUTBUFFER for getting the last executed SQL. But it seems both dm_exec_sql_text and dm_exec_input_buffer are replacement DBCC INPUTBUFFER. If this is the case then what

If rows exist in table then return value from table ELSE return a default value. – MySQL

I have to write a query which will return the latest timestamp column’s value from a table if rows exist. If there is no row(s) in table then it return the default value. I have write the following query in MS-SQL which is working fine for me. But , now I need to write this query in MySQL. I have

Copy data on parent and child table

I have two database tables. What I need to do is to copy specific data from one storage to another, but also keep the mapping to the photos. First part I can do easily writing but after that newly inserted items does not have photos. Note, that document_id field is unique for not copied items. Answer Assuming id columns are

Perform Calculation in MongoDb Query

Supposed I have the collections that contain Event type Product View water_heater View water_heater Purchase water_heater View television View television View television Purchase television There are two types of fields in the first column, (views and purchase) The second column contains different kinds of products. The above data has been imported as a collection in MongoDB database. I want to

Add a column and populate it with the queried values from another column

I have a column having dates in varchar format, I want to convert it, to date format, which I did through below query: Now, I want to create a new column and populate the column with the values that I got from above query. I am not able to do it with alter table. Any solutions? Answer Hope it works

How to create flag 0/1 inform whether was changed or not during 4 months between two columns in PROC SQL in SAS Enterprise Guide?

I have table in SAS Enterprise Guide like below: name of table: table123 date typ: ID – numeric DT – numeric VAL1 – string VAL2 – string ID DT VAL1 VAL2 123 20210523 PR P 123 20211222 P P 222 20210502 PR M 222 20210711 M PR 38 20210513 PR PR 991 20211123 M P And I need to create

Target table cannot be same one for update clause in mysql

I have a table name named ’employee’. Table creation code given below: The table content is like below: Now I want to update ‘e_id’, first it will check whether the same e_id is in the table anywhere or not, if it is not in the table then only it will update the rows with given e_id, else it will not