length

This function is used to return the length of a string.

Similar function: lengthb. The lengthb function is used to return the length of string str in bytes and return a value of the STRING type.

length(string <str>)

**Table 1** Parameter
Parameter	Mandatory	Type	Description
str	Yes	STRING	Target string to be searched for If the value is of the BIGINT, DOUBLE, DECIMAL, or DATETIME type, the value is implicitly converted to the STRING type for calculation. For other types of values, an error is reported.

The return value is of the BIGINT type.

If the value of str is not of the STRING, BIGINT, DOUBLE, DECIMAL, or DATETIME type, an error is reported.
If the value of str is NULL, NULL is returned.

Calculate the length of string abc. An example command is as follows:
The value 3 is returned.
```
select length('abc');
```
The value of the input parameter is NULL. An example command is as follows:
The value NULL is returned.
```
select length(null);
```