The following options can be used to delete duplicate rows in Oracle Database.
These examples delete duplicate rows but keep one. So if there are three identical rows for example, it deletes two of them and keeps one. This is often referred to as de-duping the table.
If you’re getting an error that reads something like “ERROR 1136 (21S01): Column count doesn’t match value count at row 2” when using the VALUES statement in MySQL, it’s probably because there’s a mismatch in the number of columns specified in the ROW() clauses.
To fix this error, be sure that all ROW() clauses contain exactly the same number of columns.
SQLite’s JSON functions and operators are now enabled by default, starting from SQLite 3.38.0 (released on 22 February 2022).
We can use SQLite’s DATE() function to return the date of the first instance of a given day of a given year. Therefore, we can use it to return the first Monday of a given year. We can also use it to return the first Tuesday, Wednesday, Thursday, Friday, etc.
We can use DATETIME() if we want a datetime value to be returned.
Below are five options for returning rows that contain uppercase letters in SQL Server.
If you’re using one of SQLite’s tabular output modes, you might find yourself battling with long lines of text that result in all subsequent columns being pushed out far to the right. This can cause you to have to keep scrolling sideways as you peruse the data.
Fortunately, there’s an easy fix.
MySQL and MariaDB have a SHOW TABLES statement, which outputs a list of tables and views in a database. PostgreSQL doesn’t have a SHOW TABLES statement, but it does have a command that produces a similar result.
In Postgres, you can use the \dt command to show a list of tables. This is a psql command (psql is the interactive terminal for PostgreSQL).
It’s possible to output query results as a JSON document when using the SQLite command line interface.
We can do this with the json output mode.
We can also use SQLite functions like json_object() and/or json_array() to return query results as a JSON document.
In SQLite, substring() is an alias for substr().
It returns a substring from a string, based on a given starting location within the string. Two arguments are required, and a third optional argument is accepted.
The substring() naming was introduced in SQLite 3.34.0, which was released on 1st December 2020. The reason that the substring() syntax was introduced was for compatibility with SQL Server.