To search if strings contain special characters, you can use REGEXP. Following is the syntax −select * from yourTableName where yourColumnName REGEXP '[^a-zA-Z0-9]';Let us first create a table −mysql> create table specialCharactersDemo    -> (    -> StudentId varchar(100)    -> ); Query OK, 0 rows affected (0.58 sec)Insert records in the table using insert command. Following is the query −mysql> insert into specialCharactersDemo values('STU_1234'); Query OK, 1 row affected (0.15 sec) mysql> insert into specialCharactersDemo values('STU567'); Query OK, 1 row affected (0.14 sec) mysql> insert into specialCharactersDemo values('STU#1234'); Query OK, 1 row affected (0.13 sec) mysql> insert into specialCharactersDemo ... Read More

To display all the fields that contain a capital letter, use the RLIKE that performs a pattern match of a string expression against a pattern.Let us first create a table −mysql> create table contains_capital_letterDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(100)    -> ); Query OK, 0 rows affected (1.42 sec)Following is the query to insert some records in the table using insert command −mysql> insert into contains_capital_letterDemo(Name) values('Larry'); Query OK, 1 row affected (0.17 sec) mysql> insert into contains_capital_letterDemo(Name) values('larry'); Query OK, 1 row affected (0.12 sec) mysql> ... Read More

To update multiple rows in a single column, use CASE statement. Let us first create a table −mysql> create table updateMultipleRowsDemo    -> (    -> StudentId int,    -> StudentMathScore int    -> ); Query OK, 0 rows affected (0.63 sec)Following is the query to insert records in the table using insert command −mysql> insert into updateMultipleRowsDemo values(10001, 67); Query OK, 1 row affected (0.14 sec) mysql> insert into updateMultipleRowsDemo values(10002, 69); Query OK, 1 row affected (0.15 sec) mysql> insert into updateMultipleRowsDemo values(10003, 89); Query OK, 1 row affected (0.14 sec) mysql> insert into updateMultipleRowsDemo values(10004, 99); Query ... Read More

To convert UNIX timestamp into a human-readable format, use the FROM_UNIXTIME() method.Let us first create a table −mysql> create table timeConversionDemo    -> (    -> dateTimeConversion bigint    -> ); Query OK, 0 rows affected (0.45 sec)Following is the query to insert records in the table using insert command −mysql> insert into timeConversionDemo values(1554316200); Query OK, 1 row affected (0.14 sec) mysql> insert into timeConversionDemo values(1546194600); Query OK, 1 row affected (0.22 sec) mysql> insert into timeConversionDemo values(1511548200 ); Query OK, 1 row affected (0.21 sec)Following is the query to display all records from the table using ... Read More

To sort more than one column at a time, you can use ORDER BY clause. Following is the syntax −select yourColumnName1, yourColumnName2, yourColumnName3 from yourTableName order by yourColumnName2, yourColumnName3;Let us first create a table −mysql> create table doubleSortDemo    -> (    -> StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> StudentName varchar(100),    -> StudentCountryName varchar(10)    -> ); Query OK, 0 rows affected (0.71 sec)Following is the query to insert records in the table using insert command −mysql> insert into doubleSortDemo(StudentName, StudentCountryName) values('John', 'AUS'); Query OK, 1 row affected (0.21 sec) mysql> insert into doubleSortDemo(StudentName, StudentCountryName) values('Sam', ... Read More

Use GROUP BY clause for this. Let us first create a table −mysql> create table sumOfFieldsDemo    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> ClientSerialNumber varchar(100),    -> ClientCost int    -> ); Query OK, 0 rows affected (0.50 sec)Following is the query to insert some records in the table using insert command −mysql> insert into sumOfFieldsDemo(ClientSerialNumber, ClientCost) values('1111', 450); Query OK, 1 row affected (0.16 sec) mysql> insert into sumOfFieldsDemo(ClientSerialNumber, ClientCost) values('2222', 550); Query OK, 1 row affected (0.15 sec) mysql> insert into sumOfFieldsDemo(ClientSerialNumber, ClientCost) values('3333', 150); Query OK, 1 row affected (0.64 ... Read More

To find if a column is auto_increment in MySQL, you can use the following syntax −select COLUMN_NAME from information_schema.columns where TABLE_SCHEMA='yourDatabaseName' and TABLE_NAME='yourTableName' and EXTRA like '%auto_increment%';Let us first create a table. Here, ClientId is set AUTO_INCREMENT −mysql> create table autoIncrementTableDemo    -> (    -> ClientId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> ClientName varchar(20),    -> ClientAge int,    -> ClientAddress varchar(100),    -> ClientCountryName varchar(100)    -> ); Query OK, 0 rows affected (0.61 sec)Now, let us find whether any of the column is auto_increment −mysql> select COLUMN_NAME from information_schema.columns where TABLE_SCHEMA='test' and TABLE_NAME='autoIncrementTableDemo' and EXTRA ... Read More

You can use NOT IN operator for the rows you do not want to delete. Following is the syntax −delete from yourTableName where yourColumnName NOT IN(‘yourValue1’, ‘yourValue2’, ‘yourValue3’, .........N);Let us first create a table −mysql> create table deleteAllRowsWithCondition    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> Name varchar(20)    -> ); Query OK, 0 rows affected (0.84 sec)Following is the query to insert some records in the table using insert command −mysql> insert into deleteAllRowsWithCondition(Name) values('Larry'); Query OK, 1 row affected (0.14 sec) mysql> insert into deleteAllRowsWithCondition(Name) values('John'); Query OK, 1 row affected ... Read More

Use trim() function to remove trailing zeroz in MySQL. Following is the syntax −select trim(yourColumnName)+0 As anyAliasName from yourTableName;Let us first create a table −mysql> create table removeTrailingZero    -> (    -> Number DECIMAL(10, 4)    -> ); Query OK, 0 rows affected (0.83 sec)Following is the query to insert some records in the table using insert command −mysql> insert into removeTrailingZero values(10.789); Query OK, 1 row affected (0.19 sec) mysql> insert into removeTrailingZero values(89.90); Query OK, 1 row affected (0.18 sec) mysql> insert into removeTrailingZero values(8999.70); Query OK, 1 row affected (0.20 sec) mysql> insert ... Read More

Use ORDER BY IF() to arrange data in a specific order. Following is the syntax −select *from yourTableName ORDER BY IF(yourColumnName=yourValue1 OR yourColumnName=yourValue2 OR yourColumnName=yourValue3, yourColumnName, ~yourColumnName) ASC;Let us first create a table −mysql> create table arrangeDataInSpecificOrder    -> (    -> StudentId int,    -> StudentName varchar(20)    -> ); Query OK, 0 rows affected (0.64 sec)Following is the query to insert some records in the table using insert command −mysql> insert into arrangeDataInSpecificOrder values(10, 'Larry'); Query OK, 1 row affected (0.12 sec) mysql> insert into arrangeDataInSpecificOrder values(15, 'Mike'); Query OK, 1 row affected (0.09 sec) mysql> insert into ... Read More