Some database management systems, including SQLite, allow us to use the VALUES keyword as a stand alone SQL statement. So we can use VALUES to return a constant table, usually with less code than would be required if we were to use the SELECT statement.
The following examples demonstrate how.
Continue readingSome RDBMSs provide an easy way for us to find out how many rows were affected by the last SQL statement. This can be handy when running INSERT, UPDATE, or DELETE statements.
The method used depends on the DBMS we’re using. Below, I look at how some of the major DBMSs implement this functionality.
Continue readingThe SQLite changes() function returns the number of database rows that were changed, inserted or deleted by the most recently completed INSERT, DELETE, or UPDATE statement, exclusive of statements in lower-level triggers.
Basically, it allows us to see how many rows are affected when we run any of those statements.
Continue readingIn SQLite, ABS() is a built-in scalar function that returns the absolute value of its argument.
The absolute value is the non-negative equivalent of the argument. It can be thought of as the distance from zero that the number resides on the number line, without considering direction.
Continue readingWhen creating a table with SQL, we can specify that the table is only to be created if it doesn’t already exist. Doing this prevents any errors from occurring in the event that the table already exists.
Here are some examples of doing this in various RDBMSs.
Continue readingWhen working with SQL, we can use the INSERT statement to insert a new row into a table. But what if we want to insert more than one row?
Fortunately, we can still use the INSERT statement. Below is a quick example that inserts multiple rows using SQL.
If you’re not sure if a table has a generated column in SQLite, you can quickly find out with either the .schema command, or by querying the sqlite_schema table.
We can use the SQL INSERT statement to insert a row into a table. We can also use it to insert more than one row.
Below are seven ways to insert multiple rows into a table in SQL. Most of these examples should work in the major RDBMSs, with the possible exception of Oracle. But no worries, I’ve included an example just for Oracle.
Continue readingIn SQLite, we can use the TIME() function to add a given number of minutes to a time value.
If we’re dealing with datetime values, we can use the DATETIME() function.
In SQLite, we can use the TIME() function to add a given number of hours to a time value.
If we’re dealing with datetime values, we can use the DATETIME() function.