Flash cards
Review the key moves
1/4
Core idea
What is the main idea behind MySQL SUBSTR() Function?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
1Quick choice
Which statement best captures the main point of this lesson?
2Fill blank
Complete the missing token from the example code.
___ SUBSTR("SQL Tutorial", 5, 3) AS ExtractString;3Order
Put the learning moves in the order that makes the concept easiest to apply.
The SUBSTR() function extracts a substring from a string (starting at any position).
Definition and Usage
MySQL SUBSTR() Function
Example
SELECT SUBSTR("SQL Tutorial", 5, 3) AS ExtractString;Definition and Usage
The SUBSTR() function extracts a substring from a string (starting at any position).
Note
The position of the first character in the string is 1.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S | Q | L | T | u | t | o | r | i | a | l |
Note
The position of the last character in the string is -1.
| -12 | -11 | -10 | -9 | -8 | -7 | -6 | -5 | -4 | -3 | -2 | -1 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| S | Q | L | T | u | t | o | r | i | a | l |
Note
The SUBSTR() and MID() functions equals to the SUBSTRING() function.
Syntax
SUBSTR(
string
,
start
,
length
)SUBSTR(
string
FROM
start
FOR
length
)Parameter Values
| Parameter | Description |
|---|---|
| string | Required. The string to extract from |
| start | Required. The start position. Can be both a positive or negative number. If it is a positive number, this function extracts from the beginning of the string. If it is a negative number, this function extracts from the end of the string. The position of the first character in the string is 1 and the position of the last character in the string is -1 |
| length | Optional. The number of characters to extract. If omitted, the whole string will be returned (from the start position) |
Technical Details
| Works in: | From MySQL 4.0 |
|---|