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The die() function can be used to stop the script and can be used to display a message to the end user. It can be used at the right side of the OR ( || ) operator and at left side can be any expression like the eval() function. Case 1 − Using die() function with no parameter The following is the output. Now we can use $! to print the error number and a message to the user in the die() function. Case 2 − Use of $! in the die() function The following is the ... Read More
Some of the popular methods of a Thread class is start, sleep, jon, and abort. Let us see the complete list of methods − Sr.No. Method & Description 1 public void Abort() Raises a ThreadAbortException in the thread on which it is invoked, to begin the process of terminating the thread. Calling this method usually terminates the thread. 2 public static LocalDataStoreSlot AllocateDataSlot() Allocates an unnamed data slot on all the threads. For better performance, use fields that are marked with the ThreadStaticAttribute attribute instead. 3 public static LocalDataStoreSlot AllocateNamedDataSlot(string name) Allocates ... Read More
In the system, the root is defined by another name as well as password. Then the user is created as a root with the help of the create command. This will result in the ERROR 1396. The query for this is given as follows − mysql> create user 'root'@'localhost' identified by 'root123'; After executing the above query, the following error is obtained − ERROR 1396 (HY000): Operation CREATE USER failed for 'root'@'localhost' The user can be created with another name and password successfully. This is given as follows − mysql> create user 'John'@'localhost' identified by ... Read More
We can know that with the help of the column name ‘UPDATED_TIME’ using information_schema.tables with WHERE clause. Let us first create a table for our example. mysql> create table MyISAMTableDemo -> ( -> id int -> ); Query OK, 0 rows affected (0.56 sec) Inserting some records into table. mysql> insert into MyISAMTableDemo values(1); Query OK, 1 row affected (0.72 sec) mysql> insert into MyISAMTableDemo values(2); Query OK, 1 row affected (0.16 sec) Syntax to know the last updated time. SELECT UPDATE_TIME FROM information_schema.tables WHERE TABLE_SCHEMA = 'yourDatabaseName' AND TABLE_NAME = ... Read More
Firstly, let us get the current datetime with the help of the now() function. mysql> select now(); The following is the output. +---------------------+ | now() | +---------------------+ | 2018-11-01 19:55:56 | +---------------------+ 1 row in set (0.00 sec) Syntax to subtract 10 days with the help of DATE_SUB() select DATE_SUB(now(),interval integer_value day ); Applying the above syntax to subtract 10 days from the current datetime. mysql> select DATE_SUB(now(),interval 10 day); Here is the output. +---------------------------------+ | DATE_SUB(now(),interval 10 day) | +---------------------------------+ | 2018-10-22 19:56:07 | +---------------------------------+ 1 row in set (0.00 sec)
MySQL has introduced signals similar to an exception in other languages. Let us first see the syntax of signal. SIGNAL SQLSTATE ' PredefinedValueforSignalError' SET MESSAGE_TEXT = 'AnyMessageInformation'; Above, we have set our own error message text as well. We will apply the above query to get an error message with the help of signals. mysql > SIGNAL SQLSTATE '42927' SET MESSAGE_TEXT = 'Error Generated'; The following is the output of the above query. ERROR 1644 (42927): Error Generated In the above output, ‘42927’ is a SQLSTATE and ‘Error Generated’ is an error message, which we added.
Let us understand the difference between initialization and assignment of values. Declaring an array. int [] n // declaring Initialization Declaring an array does not initialize the array in the memory. When the array variable is initialized, you can assign values to the array. Array is a reference type, so you need to use the new keyword to create an instance of the array. int n= new int[10]; // initialization Let’s assign value. You can assign values to individual array elements, by using the index number − n[0] = 100; n[1] = 200 ... Read More
To work with MySQL pagination, firstly let us see how to use CREATE command and use it to create a table. mysql>CREATE table RowCountDemo -> ( -> ID int, -> Name varchar(100) -> ); Query OK, 0 rows affected (0.95 sec) Records are inserted with the help of INSERT command. mysql>INSERT into RowCountDemo values(1, 'Larry'); Query OK, 1 row affected (0.15 sec) mysql>INSERT into RowCountDemo values(2, 'John'); Query OK, 1 row affected (0.13 sec) mysql>INSERT into RowCountDemo values(3, 'Bela'); Query OK, 1 row ... Read More
Firstly, check the MySQL database with DESC command. mysql>DESC mysql.db; The following is the output. +-----------------------+---------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-----------------------+---------------+------+-----+---------+-------+ | Host | char(60) | NO | PRI | | ... Read More
Float , double and a decimal are all Value Types in C#. Value type variables can be assigned a value directly. They are derived from the class System.ValueType. The value types directly contain data. Float Value Type Float is a 32-bit single-precision floating point type with range 3.4 x 1038 to + 3.4 x 1038 Memory Size is 4 bytes. float a = 3.5f; Double Value Type Double is a 64-bit double-precision floating point type with range (+/-)5.0 x 10-324 to (+/-)1.7 x 10308 Memory Size is 8 bytes. double d = 5.78788 Decimal Value ... Read More