Summary: in this tutorial, we will show you how to use the MySQL STR_TO_DATE() function to convert a string into a date time value.

Introduction to MySQL STR_TO_DATE function

The following illustrates the syntax of the STR_TO_DATE() function:

Code language: SQL (Structured Query Language) (sql)

The STR_TO_DATE() converts the str string into a date value based on the fmt format string. The STR_TO_DATE() function may return a DATE , TIME, or DATETIME value based on the input and format strings. If the input string is illegal, the STR_TO_DATE() function returns NULL.

The STR_TO_DATE() function scans the input string to match the format string. The format string may contain literal characters and format specifiers that begin with percentage (%) character. Check it out the DATE_FORMAT function for the list of format specifiers.

The STR_TO_DATE() function is very useful in data migration that involves temporal data conversion from an external format to MySQL temporal data format.

MySQL STR_TO_DATE examples

Let’s look at some examples of using STR_TO_DATE() function to convert strings into a date and/or time values

The following statement converts a string into a DATE value.

Code language: SQL (Structured Query Language) (sql)

Based on the format string ‘%d, %m, %Y’, the STR_TO_DATE() function scans the ‘21,5,2013’ input string.

• First, it attempts to find a match for the %d format specifier, which is a day of the month (01…31), in the input string. Because the number 21 matches with the %d specifier, the function takes 21 as the day value.
• Second, because the comma (,) literal character in the format string matches with the comma in the input string, the function continues to check the second format specifier %m , which is a month (01…12), and finds that the number 5 matches with the %m format specifier. It takes the number 5 as the month value.
• Third, after matching the second comma (,), the STR_TO_DATE() function keeps finding a match for the third format specifier %Y , which is four-digit year e.g., 2012,2013, etc., and it takes the number 2013 as the year value.

The STR_TO_DATE() function ignores extra characters at the end of the input string when it parses the input string based on the format string. See the following example:

Code language: SQL (Structured Query Language) (sql)

The STR_TO_DATE() sets all incomplete date values, which are not provided by the input string, to zero. See the following example:

Code language: SQL (Structured Query Language) (sql)

Because the input string only provides year value, the STR_TO_DATE() function returns a date value that has month and day set to zero.

The following example converts a time string into a TIME value:

Code language: SQL (Structured Query Language) (sql)

Similar to the unspecified date part, the STR_TO_DATE() function sets unspecified time part to zero, see the following example:

Code language: SQL (Structured Query Language) (sql)

The following example converts the string into a DATETIME value because the input string provides both date and time parts.

Code language: SQL (Structured Query Language) (sql)

In this tutorial, we have shown you various examples of using the MySQL STR_TO_DATE() function to convert strings to date and time values.