Sample table schema: Requirement: Fetch rows that match any of the tuples (col1, col2) presented in an array. SQL: I want to write this query in Go using the “database/sql” package with “github.com/lib/pq” driver, and that is where I am facing the problem. I can easily do this for sing…
Tag: database
Many-to-Many Link Table Foreign Key Modeling in SQLite
I have the following two tables in SQLite: Many Main rows may reference the same link id, and many Link rows may have the same link id, such that select * from Main natural join Link where main_id=1 will return N rows, and select * from Main where link_id=1 will return K rows. The link id is important, and th…
get all the tables within a date range
I have many weekly backup tables of the same structure and columns but with different names containing some user-specific information like this. Now I want to find the tables within a date range for example: If I choose the date range of 2021-11-20 to 2021-11-13 then the tables fetched would be user_details, …
Query monitoring changes in the field
I need to program a query where I can see the changes that certain fields have undergone in a certain date period. Example: From the CAM_CONCEN table bring those records where the ACCOUNT_NUMBER undergoes a modification in the CONCTACT field in a period of 6 months before the date. I would be grateful if you …
Generate Scripts to move a database from one server to another
I want to move a database from our testing server to my local server. I don’t have the option of back up and restore since I don’t have permission. So I decided to use the generate script option to create all the scripts for the DB and then move over the database to my local server. The problem I&…
FOR XML PATH produces only first item
I have two tables: Reservations and ReservationNights (every reservation has many nights). In a stored procedure, I have a variable that looks like this: @roomTypeList = ‘2;3;4;5;’ -> its a list of RoomUseIds. I need to display only the reservations that have a reservation nights with one of th…
How does a multi-column index work in MySQL?
More specifically, what data structure does MYSQL use for multi-column indexing? I know MYSQL use Btree for indexing, which can only index one column. How does multi-column indexing work then? Answer Think of a MySQL “composite” index this way. Concatenate all the columns in the index together, th…
How to select records from a Postgres table using an ORDER BY statement on a jsonb column that points to another table
I have two tables, characteristics and students. characteristics students The characteristics table has three columns where the id column is an auto-increment field. The name denotes the name of a specific characteristic and the value indicates the respective information about the characteristic. The students…
Checking if date in table B is between date in Table A before inserting SQLite
I have a table called Project with start and end dates. I also have a table called Plan which have its own start and end dates column. But I some way to validate that the Plans start/end date is between the matching Project start/end date. I dont know if its appropriate to add a check when I create the table
Update column of a table with new foreign key of associated table
Let’s say I have a Persons and Books table that were associated. Currently persons.usercode serves as the primary key and hence the foreign key on associated tables. I would like to change the primary key of the persons table to persons.uid. So now I want the books table to look like Dropping and adding…