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These are the functions used to perform the arithmetic operations on the column values in a table.The COUNT() function is used to return the number of rows which satisfy a certain condition.The SUM() function is used to return the sum of numerical values in a column in the table.The NULL values are ignored.SyntaxCOUNT()SELECT COUNT(column_name) FROM table_name WHERE conditionSUM()SELECT SUM(column_name) FROM table_nameSteps invloved to use count() and sum() functions on a table using MySQL in pythonimport MySQL connectorestablish connection with the connector using connect()create the cursor object using cursor() methodcreate a query using the appropriate mysql statementsexecute the SQL query using ... Read More
We can create copy of an existing table in mysql using Python. The entire table will be copied including the columns, the column definitions and all the rows of the table.SyntaxCREATE TABLE table_name SELECT * FROM existing_tabletable_name is the name of the new table to be created. existing_table is the name of the table which is to be copied.Steps to copy a table using MySQL in pythonimport MySQL connectorestablish connection with the connector using connect()create the cursor object using cursor() methodcreate a query using the appropriate mysql statementsexecute the SQL query using execute() methodclose the connectionSuppose, we have a table ... Read More
The rollback() method is one among the various methods in Python which is used to make the database transactions.Here, we will discuss about the rollback() method.The rollback() method is used to revert the last change or commit made to the database. If a condition arises such that the user is not satisfied with the changes made to the database, or if the transaction fails, then the rollback() method is operated to bring the database to its original state which was before committing the changes. This is a very important method as it helps in maintaing the integrity of the database ... Read More
The commit() method is one among the various methods in Python which is used to make the database transactions.Here, we will discuss about the commit() method. The commit() method is used to confirm the changes made by the user to the database. Whenever any change is made to the database using update or any other statements, it is necessary to commit the changes. If we donot use the commit() method after making any changes to the database, the database will not not be updated and changes will not be reflected.Syntaxdb.commit()db refers to the database connection object.Given below is an example ... Read More
LIKE is a operator in MySQL. The LIKE operator is used with the WHERE statement to search for a specific pattern in the table.Suppose you want to search for values which start with “a” in the table, the LIKE statement is used in such scenarios.There are two wildcard characters used with the LIKE clause.% − This sign represents zero, one or multiple characters._ (underscore) − This represents one single character.ExampleLIKE ‘a%’ - Searches for all the values starting with a.LIKE ‘%a’ -Searches for all the values which end with a.LIKE ‘_a%’ - Searches for all the values where ‘a’ is ... Read More
The MIN() and MAX() functions are used to perform arithmetic operations on the columns of the table.As the name suggests, the MIN() function is used to select and return the samllest value from the selected column.The MAX() function, on the other hand, selects and returns the highest value from the selected column.SyntaxMIN()SELECT MIN(column_name) FROM table_nameMAX()SELECT MAX(column_name) FROM table_nameSteps invloved in finding minimum and maximum value from a column in table using MySQL in pythonimport MySQL connectorestablish connection with the connector using connect()create the cursor object using cursor() methodcreate a query using the appropriate mysql statementsexecute the SQL query using execute() ... Read More
We can join two tables in SQL based on a common column between them or based on some specified condition. There are different types of JOIN available to join two SQL tables.Here, we will discuss about the SELF join on two tables.As the name signifies, SELF join is the join with the table itself. This join is performed between two copies of the same table. The rows of the table are matched with the other rows of the same table based on some condition.SyntaxSELECT a.coulmn1 , b.column2 FROM table_name a, table_name b WHERE condition;a and b are the two aliases ... Read More
We can join two tables in SQL based on a common column between them or based on some specified condition. There are different types of JOIN available to join two SQL tables.Here, we will discuss about the FULL join on two tables. In the FULL JOIN, all the records from both the tables are included in the result. For the records for which no matching is found, NULL is inserted on the either sides.SyntaxSELECT column1, column2... FROM table_1 FULL JOIN table_2 ON condition;Let there be two tables, “Students” and “Department” as folllows −Students+----------+--------------+-----------+ | id | Student_name | ... Read More
We can join two tables in SQL based on a common column between them or based on some specified condition. There are different types of JOIN available to join two SQL tables.Here, we will discuss about the RIGHT join on two tables.In the RIGHT JOIN, all the records from the second table or the right table are always included in the result. From the left table, the matching records are joined to the records of the right table. If there is no matching record found for a row in right table, then None is joined with that record.The tables are ... Read More
We can join two tables in SQL based on a common column between them or based on some specified condition. There are different types of JOIN available to join two SQL tables.Here, we will discuss about the LEFT join on two tables. The tables can be joined using the LEFT join. In the LEFT JOIN, all the records from the first table or the left table are always included in the result. From the right table, the matching records are joined to the records of the left table. If there is no matching record found for a row in left ... Read More