SQL Server 2022 introduced a bunch of new bit manipulation functions and operators. Amongst these are the right shift and left shift operators.
The right shift and left shift operators can be used to shift bits to the left or right. Given an integer or binary expression, these operators can shift bits by the amount that we specify.
Continue readingThe SQL EXISTS predicate is used to specify a test for a non-empty set. It returns TRUE or FALSE, depending on the outcome of the test.
When we incorporate the EXISTS predicate operator into our SQL queries, we specify a subquery to test for the existence of rows. If there are any rows, then the subquery is TRUE. If there are no rows, then the subquery is FALSE.
SQL Server 2022 introduced the IS [NOT] DISTINCT FROM predicate that compares the equality of two expressions and guarantees a true or false result, even if one or both operands are NULL.
Normally if we compare two NULL values, they will always be different (although this will depend on your ANSI_NULLS setting – setting ANSI_NULLS to OFF will result in NULLs being treated as equal). The IS [NOT] DISTINCT FROM predicate enables us to compare NULLs as though they’re equal, even when our ANSI_NULLS setting is set to ON.
If you’re using SQL Server’s GENERATE_SERIES() function/relational operator and you’re getting an empty result set, then it could be due to one of the following reasons.
If you’re using the GENERATE_SERIES() function to create a series of numbers, but you’re finding that only the first value in the series is returned, it could be something very obvious.
The obvious reason this could happen is that your step value is too big. In particular, if the step is so big that it covers the whole series, then it stands to reason that there will only be one value in the series.
If this is an issue for you, you might want to check that you’re using an appropriate step value. Using a smaller step value can help to create a series with more values.
Continue readingIn SQL Server, the GENERATE_SERIES() function is a relational operator that returns a series of values between a given start and stop point. These are returned in a single-column table.
Although the GENERATE_SERIES() function only works with numeric values, we can combine it with other functions to create a series of dates.
The GENERATE_SERIES() function was introduced in SQL Server 2022 (16.x) and requires the compatibility level to be at least 160.
The SQL UNION operator concatenates the results of two queries into a single result set. By default it returns distinct rows (i.e. it removes any redundant duplicate rows from the result set). But we can also use UNION ALL to return non-distinct rows (i.e. retain duplicates).
When it comes to NULL values, it’s pretty straight forward. SQL treats two NULL values as non distinct values. In other words, they’re duplicates.
Continue readingMySQL provides us with a bunch of functions and operators that allow us to search JSON documents for various things, such as specific values, paths, keys, etc.
Here are seven functions and three operators that search JSON documents in MySQL.
Continue readingIn MySQL, we can use the ->> operator to extract a value from a JSON document, and unquote that value.
We provide the column that contains the JSON document to the left of the operator, and the path to the value that we want to extract to the right.
The ->> operator is equivalent to JSON_UNQUOTE(JSON_EXTRACT()), and it provides the same results.
In MySQL, we can use the -> operator to extract data from a JSON document.
We provide the column that contains the JSON document to the left of the operator, and the path to the value that we want to extract to the right.
The -> operator is an alias for the two-argument form of the JSON_EXTRACT() function.