SQLite’s json_valid() function allows us to check whether a JSON string is well formed or not.
Prior to SQLite 3.45.0 the json_valid() function only accepts one argument – the value to check. However, from SQLite 3.45.0 (released on 15 January 2024), we can now provide an optional second argument to define what valid – or “well formed” – means.
If you’re getting a SQLite error that reads ‘Parse error: near “LIMIT”‘, it could be that you’re trying to use the LIMIT clause when using the VALUES clause as a stand alone statement.
SQLite doesn’t allow us to apply the LIMIT clause against the VALUES statement.
However, there is a work around. Below is an example of how we can apply the LIMIT clause against the VALUES statement.
If you’re getting an error that reads “Parse error: all VALUES must have the same number of terms” in SQLite when using the VALUES clause as a stand alone statement, it’s probably because you’re not providing the same number of columns in all rows.
When we use VALUES to create a constant table, we must provide the same number of columns in each row.
To fix this issue, be sure to provide the same number of columns across all rows.
Continue readingIf you’ve ever used the VALUES clause as a stand alone statement, you may have noticed that SQLite provides default column names for the results. SQLite conveniently names them column1, column2, and so on.
However as convenient as this is, you might want to provide names that are more meaningful.
Fortunately there’s an easy way to do that.
Continue readingIf you’re getting an error that reads ‘Parse error: near “ORDER”‘ in SQLite, it could be that you’re trying to use the ORDER BY clause when using the VALUES clause as a stand alone statement.
Although we can certainly use the VALUES clause as a stand alone SQL statement, we can’t apply the ORDER BY clause against it.
However all is not lost. Below is an example of how we can sort the results of the VALUES statement.
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 reading