MySQL Articles

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How to search a MySQL table for a specific string?

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 2K+ Views

Use equal to operator for an exact match −select *from yourTableName where yourColumnName=yourValue;Let us first create a table −mysql> create table DemoTable -> ( -> FirstName varchar(100), -> LastName varchar(100) -> ); Query OK, 0 rows affected (0.70 secInsert some records in the table using insert command −mysql> insert into DemoTable values('John', 'Smith'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('John', 'Doe'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values('Chris', 'Brown'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Carol', 'Taylor'); Query OK, 1 row affected ...

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How to update multiple rows and left pad values in MySQL?

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 481 Views

Use the LPAD() function to left pad values. Let us first create a table −mysql> create table DemoTable    -> (    -> Number int    -> ); Query OK, 0 rows affected (2.26 secInsert some records in the table using insert command −mysql> insert into DemoTable values(857786); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable values(89696); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(89049443); Query OK, 1 row affected (0.25 secDisplay all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+----------+ | ...

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Change the column name from StudentName to FirstName in MySQL?

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jun-2020 226 Views

Use CHANGE with ALTER statement. Let us first create a table −mysql> create table DemoTable -> ( -> StudentName varchar(100), -> Age int -> ); Query OK, 0 rows affected (0.84 sec)Now check the description of table −mysql> desc DemoTable;OutputThis will produce the following output −+----------------+--------------+------+-----+---------+-------+ | Field          | Type         | Null | Key | Default | Extra | +----------------+--------------+------+-----+---------+-------+ | StudentName    | varchar(100) | YES | | NULL | | | Age         ...

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Find and display duplicate values only once from a column in MySQL

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 807 Views

Let us first create a table −mysql> create table DemoTable -> ( -> value int -> ); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.34 sec) mysql> insert into DemoTable values(30); Query OK, 1 row affected (0.24 sec) mysql> insert into ...

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If I truncate a table, should I also add indexes?

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 875 Views

If you truncate a table, you do not need to add indexes because table is recreated after truncating a table and indexes get added automatically.Let us first create a table −mysql> create table DemoTable    -> (    -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    -> FirstName varchar(20),    -> LastName varchar(20)    -> ); Query OK, 0 rows affected (0.65 sec)Following is the query to create an index −mysql> create index Index_firstName_LastName on DemoTable(FirstName, LastName); Query OK, 0 rows affected (1.04 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the table using insert command −mysql> ...

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MySQL query to return a substring after delimiter?

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 991 Views

Use SUBSTRING() to return values after delimiter. Let us first create a table −mysql> create table DemoTable -> ( -> Title text -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John is good in MySQL, Sam is good in MongoDB, Mike is good in Java'); Query OK, 1 row affected (0.19 sec)Display all records from the table using select statement −mysql> select *from DemoTable;OutputThis will produce the following output −+-------------------------------------------------------------------+ | Title ...

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MySQL query to conduct a basic search for a specific last name in a column

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jun-2020 223 Views

You can use LIKE operator to conduct a basic search for last name. Let us first create a table: −mysql> create table DemoTable    -> (    -> CustomerName varchar(100),    -> CustomerAge int    -> ); Query OK, 0 rows affected (0.77 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('John Doe', 34); Query OK, 1 row affected (1.32 sec) mysql> insert into DemoTable values('David Miller', 24); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values('Bob Doe', 27); Query OK, 1 row affected (0.18 sec) mysql> insert into ...

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Calling NOW() function to fetch current date records in MySQL?

karthikeya Boyini
karthikeya Boyini
Updated on 30-Jun-2020 458 Views

Let us first create a table −mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> ShippingDate datetime -> ); Query OK, 0 rows affected (1.16 sec)Insert some records in the table using insert command. Consider current date “2019-06-28” −mysql> insert into DemoTable(ShippingDate) values('2019-01-31'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(ShippingDate) values('2019-06-06'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable(ShippingDate) values('2019-06-28'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(ShippingDate) values('2019-07-01'); Query OK, 1 row affected (0.16 sec)Display all records from the table ...

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Adding integers from a variable to a MySQL column?

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 895 Views

To set a variable, use MySQL SET. For adding integers from a variable, use UPDATE and SET as in the below syntax −set @anyVariableName:=yourValue; update yourTableName set yourColumnName=yourColumnName+ @yourVariableName;Let us first create a table −mysql> create table DemoTable -> ( -> Number int -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(20); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(40); Query OK, 1 row affected (0.15 sec) mysql> ...

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Is it impossible to add a column in MySQL specifically before another column?

Sharon Christine
Sharon Christine
Updated on 30-Jun-2020 784 Views

No, you can easily add a column before another column using ALTER.Note − To add a column at a specific position within a table row, use FIRST or AFTER col_name Let us first create a table −mysql> create table DemoTable    -> (    -> Id int,    -> Name varchar(20),    -> CountryName varchar(100)    -> ); Query OK, 0 rows affected (0.67 sec)Let us check all the column names from the table −mysql> show columns from DemoTable;OutputThis will produce the following output −+-------------+--------------+------+-----+---------+-------+ | Field       | Type         | Null | Key ...

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