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Articles on Trending Technologies
Technical articles with clear explanations and examples
Why it shows 0 instead of empty string whenever I insert an empty string into a MySQL column which is declared as NOT NULL?
It is because inserting an empty string means that we are inserting some value and not NULL. The empty string apparently maps to zero as an integer. In other words, we can say that by inserting empty string we are providing a value to MySQL that has integer representation as INT 0. Consider the following example in which we inserted an empty string and it mapped to 0 by MySQL.mysql> create table test(id int NOT NULL, Name Varchar(10)); Query OK, 0 rows affected (0.19 sec) mysql> Insert into test(id, name) values('1', 'Gaurav'), ('0', 'Rahul'), ('', 'Aarav'); Query OK, 3 ...
Read MoreHow can we find out the current transaction mode in MySQL?
We can run “SELECT @@AUTOCOMMIT” command to check the current transaction mode.mysql> Select @@AUTOCOMMIT; +--------------------+ | @@AUTOCOMMIT | +--------------------+ | 1 | +--------------------+ 1 row in set (0.05 sec) mysql> SET AUTOCOMMIT = 0; Query OK, 0 rows affected (0.00 sec) mysql> Select @@AUTOCOMMIT; +--------------------+ | @@AUTOCOMMIT | +--------------------+ | 0 | +--------------------+ 1 row in set (0.00 sec)
Read MoreCreating a Radio button group in ABAP Screen Painter
Screen Painter is known as an ABAP editor tool that can be used to create a screen. Screen Painter is used to create and manage all the elements in a screen.Transaction Code SE51There are various ways you can insert a Radio button to ABAP Screen Painter. First is by clicking on the radio button symbol on the left, then click on the canvas on the right to insert a radio button. You can repeat this for each button.Another option is that you open the dictionary window (blue rectangle with a smaller red rectangle inside). Type the variable name you used ...
Read MoreConverting date type SYDATUM in a format like MM/DD/YY in SAP ABAP
It depends if you want to write it to a list screen or you want to convert it to a text variable. To write it to a list screen, you can use below code −WRITE I_my_dateMM/DD/YYYYTo convert it to a text variable, you can use below command −WRITE l_my_dateTO l_my_text MM/DD/YYYYIf you want to set the date in SAPscript form, you can use SET DATE MASK command. You can specify date fields to be printed in specified format −/: SET DATE MASK= 'date_mask'In the date mask, you can use the following codes −DD: day (two digits) DDD: day name - ...
Read MoreWhat happens if MySQL query returns no rows?
From the output returned by MySQL, it is very much clear that how many rows are there in the result set along with the execution time.ExampleFor example, in the following MySQL output we can see there are 3 rows in the result set.mysql> Select * from ratelist ORDER BY Price LIMIT 3; +----+------+-------+ | Sr | Item | Price | +----+------+-------+ | 5 | T | 250 | | 1 | A | 502 | | 2 | B | 630 | +----+------+-------+ 3 rows in set (0.00 sec)But suppose if MySQL query has ...
Read MoreWhat is the use of underscore keyword in Java 9?
In earlier versions of Java, the underscore ("_") has used as an identifier or to create a variable name. Since Java 9, the underscore character is a reserved keyword and can't be used as an identifier or variable name. If we use a single underscore character as an identifier, the program fails to compile and throws a compile-time error because now it is a keyword and can't be used as a variable name in Java 9 or later versions.Examplepublic class UnderscoreKeywordTest { public static void main(String args[]) { int _ = ...
Read MoreWhile connecting to one MySQL database, how can I see the list of tables of other MySQL database?
With the help of SHOW TABLES From Database_name query, we can see the tables of another database. Here Database_name is the name of the database which we are not using currently. Consider the following example in which we run the query for getting the list of tables in database name ‘tutorial’.mysql> show tables from tutorial; +--------------------+ | Tables_in_tutorial | +--------------------+ | employee | | showzerofill | | student | +--------------------+ 3 rows in set (0.00 sec)
Read MoreHow do we count the total duplicate records in a column of MySQL table?
Suppose we have the following table named stock_item in which the column quantity is having duplicate values i.e. for item name ‘Notebooks’ and ‘Pencil’, the column ‘Quantity’ is having duplicate values ‘40’ and for items ‘Shirts’, ‘Shoes’ and ‘Trousers’ triplicate value 29 is hold by column ‘quantity’ as shown in the table.mysql> Select * from stock_item; +------------+----------+ | item_name |quantity | +------------+----------+ | Calculator | 89 | | Notebooks | 40 | | Pencil | 40 | | Pens | 32 | | ...
Read MoreHow MySQL stored function evaluates if it got NULL value while using the dynamic values from a table?
In such kind of cases when a stored function got NULL values then it will return NULL as the result. It can be understood from the example below in which we have a NULL value in the records of student ‘Mohit’. Now, when we will apply the stored function ‘avg_marks’ on this data, it will return NULL as result.mysql> Select * from Student_marks; +-------+------+---------+---------+---------+ | Name | Math | English | Science | History | +-------+------+---------+---------+---------+ | Raman | 95 | 89 | 85 | 81 | | Rahul | 90 | ...
Read MoreHow can we create a MySQL stored function that uses the dynamic data from a table?
MySQL Stored functions can reference tables but they cannot make use of statements that return a result set. Hence we can say that there is no SELECT query that returns result set. But we can have SELECT INTO to get rid of that. For example, we are creating a function ‘Avg_marks’ that uses the dynamic data from table named ‘Student_marks’, having following records, to calculate the average of marks.mysql> Select * from Student_marks; +-------+------+---------+---------+---------+ | Name | Math | English | Science | History | +-------+------+---------+---------+---------+ | Raman | 95 | 89 | 85 | ...
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