In SQL, LPAD()is a commonly used function that pads the left part of a string with a specified character. The function can be used on strings and numbers, although depending on the DBMS, numbers may have to be passed as a string before they can be padded.
DBMSs that have an LPAD() function include MySQL, MariaDB, PostgreSQL, and Oracle.
DBMSs that don’t have an LPAD() function include SQL Server and SQLite (although there are other ways to apply left padding in these DBMSs).
In SQL, RPAD()is used to pad the right part of a string with a specified character. The function can be used on strings and numbers, although depending on the DBMS, numbers may have to be passed as a string before they can be padded.
DBMSs that have an RPAD() function include MySQL, MariaDB, PostgreSQL, and Oracle.
DBMSs that don’t have an RPAD() function include SQL Server and SQLite.
In most cases, concatenating a string and a number in SQL is no different to concatenating two strings.
Most DBMSs will concatenate the string and number as if they were both strings. This is because the number is usually converted to a string before the concatenation operation.
Continue readingBelow are examples of adding a leading zero to a number in SQL, using various DBMSs.
Continue readingSome RDBMSs provide an LPAD() and RPAD() function that enables us to left pad or right pad a string. Some functions also allow us to add leading or trailing zeros numbers.
Below are examples of applying SQL padding in some of the more popular RDBMSs.
Continue readingMost of the major RDBMSs provide several options for concatenating two or more strings.
CONCAT() function, which concatenates its arguments.CONCAT_WS() that allows you to specify a separator that separates the concatenated strings.Below are examples of each method.
Continue readingMost major RDBMSs provide at least one function that enables us to return the month name from a date.
Continue readingIn SQL Server, you can use the sp_rename stored procedure to rename an object, including a column.
In SQL, you can join three tables or more by adding another join after the first one.
You can also run nested joins by specifying one join as the join condition for another.
Continue readingIn SQL, you can use the ALTER TABLE statement to add one or more columns to an existing table.
To do this, use the ADD clause, followed by the column definition. Separate multiple columns with a comma.
Only specify ADD once (i.e. there’s no need to specify it for each column).