Why 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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