Expressions are those of one or more values, operators, and calculated values
SQL
A combination of functions.
Hypothetical There are different types of Hypothetical The following example demonstrates These expressions are used to perform any mathematical operations in the query. The syntax is as follows: Here, numerical_expression is used for mathematical expressions or any formula. The following example demonstrates the use of SQLite numeric expressions: There are several built-in functions, such as Date expressions return the current system date and time values, and these expressions will be used for various data operations.
SQL
Expressions, like formulas, are written in the query language. You can also use specific datasets to query the database. 1.15.1. Grammar ¶
SELECT
The basic syntax of the statement is as follows:SELECT column1, column2, columnN
FROM table_name
WHERE [CONDITION | EXPRESSION];
SQLite
The expression is explained as follows: 1.15.2. SQLite-Boolean expression ¶
SQLite
Gets the data on the basis of matching a single value The syntax is as follows:SELECT column1, column2, columnN
FROM table_name
WHERE SINGLE VALUE MATCHING EXPRESSION;
COMPANY
The table has the following records:ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
SQLite
Usage of Boolean expressions:sqlite> SELECT * FROM COMPANY WHERE SALARY = 10000;
ID NAME AGE ADDRESS SALARY
---------- ---------- ---------- ---------- ----------
4 James 24 Houston 10000.0
1.15.3. SQLite-numeric expression ¶
SELECT numerical_expression as OPERATION_NAME
[FROM table_name WHERE CONDITION] ;
sqlite> SELECT (15 + 6) AS ADDITION
ADDITION = 21
avg()
、
sum()
、
count()
, and so on, to perform a summary data calculation called a table or a specific table column.sqlite> SELECT COUNT(*) AS "RECORDS" FROM COMPANY;
RECORDS = 7
1.15.4. SQLite-date expression ¶
sqlite> SELECT CURRENT_TIMESTAMP;
CURRENT_TIMESTAMP = 2013-03-17 10:43:35