MYSQL CONCAT FAILS ON NULL CODE
) Engine= InnoDB Code language: SQL (Structured Query Language) ( sql ) (We make the posts table as simple as possible for the demonstration purpose).įirst, we create the posts table by using the CREATE TABLE statement: CREATE TABLE posts( Suppose we have a posts table that stores blog posts with four columns postid, title, excerpt and content. SELECT Code language: SQL (Structured Query Language) ( sql ) An application of MySQL string length functions See the following example: SET = CONVERT( 'á' USING utf8) However, if a string has special characters, the result is different. The CHAR_LENGTH and LENGTH returns the same result. Notice that some character sets hold characters whose number of bytes can be varied e.g., for the utf8 character set: SET = CONVERT( 'MySQL String Length' USING utf8) The latin1 character set contains 1-byte characters therefore, its length in bytes and its length in character are equal. We use the latin1 character set for the string. The following statements demonstrate how the LENGTH and CHAR_LENGTH functions that work with 1-byte characters: SET = CONVERT( 'MySQL string length' USING latin1) Because the string contains 2-byte characters, its length in character is 19, while its length in bytes is 38. Second, we use the CHAR_LENGTH and LENGTH functions to get the length of the string in bytes and in characters.First, we convert the MySQL String Length string into ucs2 character set, which is UCS-2 Unicode that holds 2-byte characters.SELECT Code language: SQL (Structured Query Language) ( sql ) Let’s take a look at the following statements: SET = CONVERT( 'MySQL String Length' USING ucs2) You use the CHAR_LENGTH function to get the length of a string measured in characters as follows: CHAR_LENGTH(str) Code language: SQL (Structured Query Language) ( sql ) Examples of LENGTH and CHAR_LENGTH functions To get the length of a string measured in bytes, you use the LENGTH function as follows: LENGTH(str) Code language: SQL (Structured Query Language) ( sql ) However, if a string contains multi-byte characters, its length in bytes is typically greater than its length in characters. If a string contains 1-byte characters, its length measured in characters and its length measured in bytes are equal. The Maxlen column stores the number of bytes for character sets. In MySQL, a string can be in any character set. SHOW CHARACTER SET Code language: SQL (Structured Query Language) ( sql ) You use the SHOW CHARACTER SET statement to get all character sets supported by MySQL database server. MySQL supports various character sets such as latin1, utf8, etc. Summary: in this tutorial, you will learn about MySQL string length functions that allow you to get the length of strings measured in bytes and in characters.
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