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Articles on Trending Technologies
Technical articles with clear explanations and examples
Fix Error in MySQL syntax while creating a table column with name "index"?
You can’t use the index as a column name because it is a reserved word. For this, you need to use backticks around the column name.If you will use a reserved word as the column name, you can see the following error−mysql> create table DemoTable -> ( -> Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> index int -> )ENGINE=MyISAM; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'int )ENGINE=MyISAM' at line 4Let us first ...
Read MoreDisplay USD currency records with the correct format in MySQL
Use FORMAT() in MySQL to display USD currency records in the correct form. Let us first create a table −mysql> create table DemoTable -> ( -> Amount DECIMAL(15, 4) -> ); Query OK, 0 rows affected (0.75 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(90948484); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(1000000000); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(1535353536); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values(773646463); Query OK, 1 row affected (0.20 sec)Display all records from ...
Read MoreShuffling column values with MySQL?
To shuffle elements, you need to use ORDER BY RAND(). Let us first create a table −mysql> create table DemoTable1557 -> ( -> SubjectId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> SubjectName varchar(20) -> ); Query OK, 0 rows affected (0.91 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1557(SubjectName) values('MySQL'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1557(SubjectName) values('MongoDB'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1557(SubjectName) values('Java'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1557(SubjectName) values('C'); Query OK, 1 row affected ...
Read MoreUpdate MySQL table on INSERT command with triggers?
Let us first create a table −mysql> create table DemoTable1 -> ( -> Id int, -> FirstName varchar(20) -> ); Query OK, 0 rows affected (0.52 sec)Here is the query to create second table −mysql> create table DemoTable2 -> ( -> EmployeeId int, -> EmployeeName varchar(20) -> ); Query OK, 0 rows affected (0.51 sec)Let us now create a trigger to update MySQL table on insert command −mysql> DELIMITER // mysql> CREATE TRIGGER updateDemoOnInsert -> AFTER INSERT ON DemoTable2 -> FOR EACH ...
Read MoreQuickly search for a string in MySQL database?
Use FULLTEXT search to quickly search for a string. Let us first create a table −mysql> create table DemoTable1554 -> ( -> Title text -> ); Query OK, 0 rows affected (0.63 sec)Here is the query to create full text search −mysql> create fulltext index faster_title on DemoTable1554(Title); Query OK, 0 rows affected, 1 warning (7.09 sec) Records: 0 Duplicates: 0 Warnings: 1Insert some records in the table using insert command −mysql> insert into DemoTable1554 values('John is working on MySQL database'); Query OK, 1 row affected (0.26 sec) mysql> insert into DemoTable1554 values('Adam Smith is working on ...
Read MoreDisplay an error while inserting duplicate records in a MySQL table
For this, you can use UNIQUE KEY. Let us first create a table −mysql> create table DemoTable1553 -> ( -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> EmployeeName varchar(20), -> EmployeeSalary int -> ); Query OK, 0 rows affected (0.47 sec)Here is the query to add unique key −mysql> alter table DemoTable1553 add unique(EmployeeSalary); Query OK, 0 rows affected (0.53 sec) Records: 0 Duplicates: 0 Warnings: 0Insert some records in the table using insert command −mysql> insert into DemoTable1553(EmployeeName, EmployeeSalary) values('Chris', 45000); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable1553(EmployeeName, EmployeeSalary) ...
Read MoreWhy does the update command in MySQL insist on using slanted single quotes?
Use single quotes on string input value. If there is an identifier like table name or column name, then do not use single quotes (use backticks).Let us first create a table −mysql> create table DemoTable1552 -> ( -> `key` int, -> Name varchar(20) -> ); Query OK, 0 rows affected (0.82 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1552 values(101, 'Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1552 values(102, 'David'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable1552 values(103, 'Mike'); Query OK, 1 row ...
Read MoreHow to select only 3 ordered rows on a MySQL table?
For this, you can use ORDER BY clause along with LIMIT. Let us first create a table −mysql> create table DemoTable1551 -> ( -> EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY, -> EmployeeName varchar(20) -> ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1551(EmployeeName) values('Chris'); Query OK, 1 row affected (0.25 sec) mysql> insert into DemoTable1551(EmployeeName) values('Robert'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable1551(EmployeeName) values('Mike'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1551(EmployeeName) values('Sam'); Query OK, 1 row ...
Read MoreMaintain the custom order of the IDs passed in MySQL
To maintain the custom order of IDs, use ORDER BY CASE statement. Let us first create a table −mysql> create table DemoTable1550 -> ( -> Id int, -> Name varchar(20) -> ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1550 values(101, 'Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable1550 values(110, 'Bob'); Query OK, 1 row affected (0.29 sec) mysql> insert into DemoTable1550 values(105, 'Carol'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable1550 values(109, 'Mike'); Query OK, 1 row ...
Read MoreHow to detect encoding and mixed line endings (Windows and Unix) in SAP?
You can make use of CL_ABAP_FILE_UTILITIES => CHECK_FOR_BOM to define file encoding type and use constantly of class CL_ABAP_CHAR_UTILITIES to process the files.ClassCL_ABAP_CHAR_UTILITIESShort DescriptionUtilities for Processing Characters
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