In the world of programming, dealing with different data types may be a regular part of your routine. While some programming languages offer typecasting, some do not offer that luxury. Fortunately, if you use SQL databases, you can use the CONVERT function to convert data from one datatype to another. In this article, we'll discuss the CONVERT function and how you can use it to convert data types.

What is the CONVERT Function?

The CONVERT function is a SQL Server function that converts the datatype of an expression or value to another datatype. It takes two arguments: the expression or value to be converted and the target datatype to which the expression or value should be converted. It's important to note that CONVERT doesn't change the original data. It only returns a new value that's converted to the specified datatype.

Syntax of the CONVERT Function

The syntax of the CONVERT function in SQL Server is as follows:

```

CONVERT(data_type[(length)], expression, style)

```

- `data_type`: The target data type to which the expression or value should be converted.

- `length`: The length of the target data type (for example, for `VARCHAR(n)`, `n` represents the length).

- `expression`: The expression or value to be converted.

- `style`: The optional formatting style to be applied to the expression or value.

Available Conversion Data Types

SQL Server supports a variety of data types that can be used with the CONVERT function. Here are some of the available data types:

- `BIGINT`

- `BINARY`

- `BIT`

- `CHAR`

- `DATE`

- `DATETIME`

- `DECIMAL`

- `FLOAT`

- `IMAGE`

- `INT`

- `MONEY`

- `NCHAR`

- `NTEXT`

- `NUMERIC`

- `NVARCHAR`

- `REAL`

- `SMALLDATETIME`

- `SMALLINT`

- `SMALLMONEY`

- `TEXT`

- `TIME`

- `TIMESTAMP`

- `TINYINT`

- `UNIQUEIDENTIFIER`

- `VARBINARY`

- `VARCHAR`

Conversion Examples

Let's take a look at some examples of how to use the CONVERT function:

1. String to Integer

```

SELECT CONVERT(INT, '101')

```

The above code will convert the string '101' to the integer 101.

2. String to Date

```

SELECT CONVERT(DATE, '2022-04-03')

```

The above code will convert the string '2022-04-03' to the date format.

3. Float to Integer

```

SELECT CONVERT(INT, 25.5)

```

The above code will convert the float 25.5 to the integer 25.

4. Date to String

```

SELECT CONVERT(VARCHAR(10), GETDATE(), 101)

```

The above code will convert a date to a string in American date format. The result will look like '04/03/2022'.

5. Integer to String

```

SELECT CONVERT(VARCHAR(3), 42)

```

The above code will convert the integer value 42 to a string datatype.

Conclusion

In conclusion, the CONVERT function in SQL Server is a useful tool for converting data types. It allows you to change the datatype of a value without altering the value itself. Moreover, the CONVERT function can be used for several different data types, giving you a wider range of options when working with your data. Hopefully, this article has helped you understand how the CONVERT function works and how you can use it effectively to convert data types.