Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
Articles by Ankith Reddy
Page 65 of 73
Set MySQL DECIMAL with accuracy of 10 digits after the comma?
As you know the DECIMAL() method takes two parameter. The first parameter tells about the total number of digits and second parameter tells about number of digits after decimal point. Therefore, if you use DECIMAL(10, 10) that means you can use only 10 fractional digit.For Example: Store 0.9999999999 with DECIMAL(20, 10).To understand what we discussed above, let us create a table. The query to create a table is as follows:mysql> create table Decimal_Demo -> ( -> Id int NOT NULL AUTO_INCREMENT, -> Price DECIMAL(20, 10), -> PRIMARY KEY(Id) ...
Read MoreHow to select yesterday's date in MySQL?
To select yesterday’s date, use the subdate() function from MySQL. The syntax is as followsselect subdate(yourDatetimeColumnName) as anyVariableName from yourTableName;To understand the above syntax, let us create a tablemysql> create table YesterdayDateDemo -> ( -> VisitedDateTime datetime -> ); Query OK, 0 rows affected (0.59 sec)Let us now insert date in the table using insert command. The query is as followsmysql> insert into YesterdayDateDemo values(now()); Query OK, 1 row affected (0.15 sec) mysql> insert into YesterdayDateDemo values('2012-12-26 13:24:35'); Query OK, 1 row affected (0.17 sec) mysql> insert into YesterdayDateDemo values('2013-10-22 12:20:32'); Query OK, 1 row affected (0.16 sec)Let ...
Read MoreFind rows where column value ends with a specific substring in MySQL?
To find rows and update with new value where column value ends with specific substring you need to use LIKE operator.The syntax is as follows:UPDATE yourTableName SET yourColumnName=’yourValue’ WHERE yourColumnName LIKE ‘%.yourString’;To understand the above syntax, let us create a table. The query to create a table is as follows:mysql> create table RowEndsWithSpecificString -> ( -> Id int NOT NULL AUTO_INCREMENT, -> FileName varchar(30), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (1.50 sec)Now you can insert some records in the table using ...
Read MoreGenerate the row count (serial number) of records after returning the result in MySQL query?
To generate serial number i.e. row count in MySQL query, use the following syntax.SELECT @yourVariableName − = @yourVariableName+1 anyAliasName, yourColumnName1, yourColumnName2, yourColumnName3, ....N from yourTableName , (select @yourVariableName − = 0) as yourVariableName;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table tblStudentInformation -> ( -> StudentName varchar(20), -> StudentAge int, -> StudentMathMarks int -> ); Query OK, 0 rows affected (0.68 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into tblStudentInformation values('Carol', ...
Read MoreNeed help selecting non-empty column values from MySQL?
Select non-empty column values using NOT IS NULL and TRIM() function. The syntax is as follows.SELECT * FROM yourTableName WHERE yourColumnName IS NOT NULL AND TRIM(yourColumnName) ' ';You can select non-empty value as well as whitespace from column using the same TRIM() function.To understand the syntax we discussed above, let us create a table. The query to create a table is as follows −mysql> create table SelectNonEmptyValues -> ( -> Id int not null auto_increment, -> Name varchar(30), -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.62 sec)Insert records in the table ...
Read MoreHow can we use nested transactions in MySQL?
We can work with nested transactions in MySQL with the help of SAVEPOINT.Firstly, create a table. After that, begin the transaction.Now, insert records in the table created above. Use SAVEPOINT statement to set a named transaction savepoint with a name of identifier.Here are all the steps shown in the form of query −Create tablemysql> create table NestedTransactionDemo -> ( -> Name varchar(200) -> ); Query OK, 0 rows affected (0.63 sec)Start the transaction −mysql> START TRANSACTION; Query OK, 0 rows affected (0.00 sec)Now, insert a record in the tablemysql> insert into ...
Read MorePython Low-level threading API
The '_thread' module in Python library provides a low-level interface for working with light-weight processes having multiple threads sharing a global data space. For synchronization, simple locks (also called mutexes or binary semaphores) are defined in this module. The 'threading' built-in module provides a higher-level threading API built on top of this module.start_new_thread()This module-level function is used to open a new thread in the current process. The function takes a function object as an argument. This function gets invoked on successful creation of the new thread. The span of this function corresponds to the lifespan of the thread. The thread ...
Read MoreHow to find the MySQL data directory from command line in Windows?
To find the MySQL data directory, we can simply use the variable datadir. Let us see how to use the variable with select statement.The query is as follows −mysql> select @@datadir;Here is the output+---------------------------------------------+ | @@datadir | +---------------------------------------------+ | C:\ProgramData\MySQL\MySQL Server 8.0\Data\ | +---------------------------------------------+ 1 row in set (0.00 sec)Now we can reach the directory from the above sample output.Here is the snapshot that displays the MySQL data directory.
Read MorePython Binary Data Services
Provisions of the struct module in the Python library are useful in performing conversions between C type structs and Python bytes objects. This can be achieved by module level functions as well as Struct class and its methods as defined in the struct module.The conversion functions use a format string. The byte order, size, and alignment used in the format string is determined by formatting character as per the following tableCharacterByte orderSizeAlignment@nativenativenative=nativestandardnonebig-endianstandardnone!network (= big-endian)standardnoneFollowing table shows format characters used to denote C type variables and corresponding Python types.FormatC TypePython typexpad byteno valueccharbytes of length 1b/Bsigned/unsigned charinteger?_Boolboolh/Hshort/unsigned shortintegeri/Iint/unsigned intintegerl/Llong/unsigned longintegerffloatfloatddoublefloatschar[]bytespchar[]bytesPvoid *integerFollowing ...
Read MoreFinding modules used by a Python script (modulefinder)
The ModuleFinder class in 'modulefinder' module can determine set of modules imported by a certain script. This module has a command line interface as well as programmatic interface.For demonstration of functionality, use following script#modfinder.py import hello try: import trianglebrowser import nomodule, mymodule except ImportError: passCommand line interfaceFollowing command displays list of modules located as well as not found.E:\python37>python -m modulefinder modfinder.pyOutputName File ---- ---- m __main__ modfinder.py m hello hello.py m math m trianglebrowser trianglebrowser.py Missing modules: ? mymodule imported from __main__ ? nomodule imported from __main__Programmatic interfaceModuleFinder class in ...
Read More