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HomeDatabaseMysql TutorialWhy do we need to add backticks in mysql statements?

In MySQL we sometimes often encounter backticks (``). At first I didn’t know what they meant. What is their function?


Select * from `member` order by posts desc limit 0,10;


It is to distinguish MYSQL’s reserved words from ordinary ones Symbols introduced by characters.

For example: SELECT `select` FROM `test` WHERE select='Field value'

In the test table , there is a select field. If no backticks are used, MYSQL will regard select as a reserved word and cause an error. Therefore, if has a MYSQL reserved word as a field, backticks must be added to distinguish .

Quotation marks are generally used in field values. If the field value is a character or string, Then add quotation marks , such as: select='field value'

Tables built without backticks cannot contain MYSQL Reserved words, otherwise an error will occur

Backtick `, the symbol to the left of the number 1.

Reserved words cannot be used in table names , such as desc. In this case, backticks need to be added to distinguish them, but backticks can be ignored when using table names.

create table desc error

create table `desc` successful

create table `test `Success

drop table test success

Reserved words cannot be used for field names, such as desc, at this time Backticks need to be added, and backticks must also be added when using insert, etc.

create table `test`(`desc` varchar(255)) succeeded

insert into test(desc) values('fxf' ) failed

insert into test(`desc`) values('fxf')success

Mysql common reserved words


##Be sure to pay attention when using mysql , do not use its reserved words as table names or column names, otherwise inexplicable errors will occur.

Yesterday I created a table with a column named interval (time interval). As a result, the data could not be inserted. Finally, I discovered that interval is a reserved word of MySQL.

If similar errors occur in the future, first think about whether it is caused by table name or column name conflicts.

I found a MySQL reserved word list from the Internet for reference only.


##TABLETERMINATEDTHENTINYBLOBTINYINTTINYTEXTTOTRAILINGTRIGGERTRUEUNDO##UNIQUEUPDATEUSINGUTC_TIMESTAMPVARCHAR##WHENWHEREWITHWRITEX509YEAR_MONTH Note: MySQL allows some keywords to be used as unquoted identifiers because many people have used them before. Such as: ACTION
ADD ALL ALTER
ANALYZE AND AS
ASC ASENSITIVE BEFORE
BETWEEN BIGINT BINARY
BLOB BOTH BY
CALL CASCADE CASE
CHANGE CHAR CHARACTER
CHECK COLLATE COLUMN
CONDITION CONNECTION CONSTRAINT
CONTINUE CONVERT CREATE
CROSS CURRENT_DATE CURRENT_TIME
CURRENT_TIMESTAMP CURRENT_USER CURSOR
DATABASE DATABASES DAY_HOUR
DAY_MICROSECOND DAY_MINUTE DAY_SECOND
DEC DECIMAL DECLARE
DEFAULT DELAYED DELETE
DESC DESCRIBE DETERMINISTIC
DISTINCT DISTINCTROW p
DOUBLE DROP DUAL
EACH ELSE ELSEIF
ENCLOSED ESCAPED EXISTS
EXIT EXPLAIN FALSE
FETCH FLOAT FLOAT4
FLOAT8 FOR FORCE
FOREIGN FROM FULLTEXT
GOTO GRANT GROUP
HAVING HIGH_PRIORITY HOUR_MICROSECOND
HOUR_MINUTE HOUR_SECOND IF
IGNORE IN INDEX
INFILE INNER INOUT
INSENSITIVE INSERT INT
INT1 INT2 INT3
INT4 INT8 INTEGER
INTERVAL INTO IS
ITERATE JOIN KEY
KEYS KILL LABEL
LEADING LEAVE LEFT
LIKE LIMIT LINEAR
LINES LOAD LOCALTIME
LOCALTIMESTAMP LOCK LONG
LONGBLOB LONGTEXT LOOP
LOW_PRIORITY MATCH MEDIUMBLOB
MEDIUMINT MEDIUMTEXT MIDDLEINT
MINUTE_MICROSECOND MINUTE_SECOND MOD
MODIFIES NATURAL NOT
NO_WRITE_TO_BINLOG NULL NUMERIC
ON OPTIMIZE OPTION
OPTIONALLY OR ORDER
OUT OUTER OUTFILE
PRECISION PRIMARY PROCEDURE
PURGE RAID0 RANGE
READ READS REAL
REFERENCES REGEXP RELEASE
RENAME REPEAT REPLACE
REQUIRE RESTRICT RETURN
REVOKE RIGHT RLIKE
SCHEMA SCHEMAS SECOND_MICROSECOND
SELECT SENSITIVE SEPARATOR
SET SHOW SMALLINT
SPATIAL SPECIFIC SQL
SQLEXCEPTION SQLSTATE SQLWARNING
SQL_BIG_RESULT SQL_CALC_FOUND_ROWS SQL_SMALL_RESULT
SSL STARTING STRAIGHT_JOIN
UNION
UNLOCK UNSIGNED
USAGE USE
UTC_DATE UTC_TIME
VALUES VARBINARY
VARCHARACTER VARYING
WHILE
##XOR
ZEROFILL
, BIT, DATE, ENUM, NO, TEXT, TIME, TIMESTAMP

##so for

safety
For the sake of convenience, you can add `` to both the table name and the field name.

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