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w can I parse a string into a specific data type in SQL?
When dealing with data in SQL, one of the common tasks you might encounter is converting (or parsing) a string into a specific data type. This may come in handy when the data stored in your database is not in the format you need for your calculations or data analysis. This post will show you how you can perform this conversion using SQL queries.
1. Introduction to Data Type Conversion
In SQL, you’re allowed to convert data types explicitly using built-in SQL functions. The standard functions that you’ll often use for converting a string into a different data type are CAST() and CONVERT(). Let’s take a look at how we can use these functions.
2. Using the CAST() Function
The CAST function is used to convert a data type variable or data from one data type to another data type. The syntax of the CAST function is as follows:
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CAST (expression AS data_type) |
Let’s take an example where we are converting a string value ‘12345’ to an integer data type:
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SELECT CAST('12345' AS INT) AS String_to_Integer; |
When executed, the above SQL statement converts the string ‘12345’ to integer 12345.
3. Using the CONVERT() Function
The CONVERT() function is used to change the data type of a column into another data type. The syntax is as follows:
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CONVERT(data_type(length), expression, style) |
Here’s how to convert a string ‘2020-12-31’ into a date:
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SELECT CONVERT(DATE, '2020-12-31') AS String_to_Date; |
When the above SQL statement is executed, it will convert the string ‘2020-12-31’ into a date 2020-12-31.
4. Conclusion
As you can see, transforming a string into a specific data type in SQL is straightforward thanks to the CAST() and CONVERT() functions. Always remember to use the function that matches your needs and the data type you’re aiming to cast or convert to.