Relational Database Management Systems (RDBMS) are based on the relational model invented by Edgar F. Codd. They store data in the form of tables, and allow the data to be linked by establishing a relationship between the tables. MySQL and SQLite are both based on the relational database management system [...]
A schema is a collection of database objects (tables, views, functions, indexes ,etc) associated with one particular database username. This username is called the schema owner. A database can have one or multiple schemas. An object within a schema is qualified using the schema_name.object_name format. Say a user's database username [...]
MySQL provides various built-in functions for numerical operations. Commonly used functions are ABS()CEIL()FLOOR()ROUND()MOD()RAND()POW()TRUNCATE()DIV ABS() It returns the absolute (positive) value of a number. Following shows the syntax of the ABS() function ABS(number) number is a literal number or an expression that evaluates to a number. In case number is zero [...]
SOUNDEX() This function accepts a string and converts it to a four-character code based on how the string sounds when it is spoken. The first character is the first letter of the phrase. Vowels are omitted unless the first letter of the phrase is a vowel and the other three [...]
Introduction MySql provides various function to convert a number from one base to other base. Commonly used function for base conversion are BIN()OCT()HEX()CONV() BIN() This function is used for converting from decimal to binary. Syntax of the function is BIN(number) number is the decimal number you want to convert to [...]
Introduction A regular expression is a special string that describes a search pattern. The advantage of using regular expression is that you are not limited to search for a string based on a fixed pattern with the percent sign (%) and underscore (_) in the LIKE operator. Syntax Syntax of [...]
Introduction CASE expression allows to evaluate a list of conditions and returns one of the possible results. The CASE expression has two formats. Syntax The following illustrates the simple CASE expression: CASE expression WHEN expression_1 THEN result_1 WHEN expression_2 THEN result_2 WHEN expression_3 THEN result_3 … ELSE else_result END CASE [...]
Introduction Arithmetic operators can perform arithmetical operations on numeric operands involved. Arithmetic operators are Addition (+)Subtraction (-)Multiplication (*)Division (/)Modulo (%) Operator Precedence A statement having multiple operators is evaluated based on the priority of operators. If all the operators have equal precedence, then the operators are evaluated from left to [...]
Introduction Logical operator allows to test for the truth of a condition. Similar to a comparison operator, a logical operator returns a value of true, false, or unknown. Logical operators are: OperatorDescriptionANDReturn true if both expressions are trueORReturn true if either expression is trueNOTToggle a single boolean argumentLogical Operators AND [...]
SQL comparison operators allow you to test if two expressions are the same. The result of a comparison can be TRUE, FALSE, or UNKNOWN (an operator that has one or two NULL expressions returns UNKNOWN). List of operators that can be used while specifying condition are OperatorDescription=Equal to!=Not Equal to<Less [...]