1. 词汇
filter condition
search criteria
2. 专有名词 Term - Page 8
Row
Row is a record in table, and technically the correct term.
3. 概念 NULL - Page 39
Rows with NULL will not be returned when filter selects all rows that do not have a particular value.
例子1
SELECT prod_name FROM Products WHERE prod_price IS NULL;
4. 概念
AND 优先级比 OR 高
5. 概念 OR
If the first condition was met, the row would be retrived regardless of the second condition.
例子1
SELECT prod_id, prod_price, prod_name FROM Products WHERE vend_id = 'DLL01' OR vend_id = 'BRS01';
例子2
SELECT prod_id, prod_price, prod_name FROM Products WHERE vend_id IN ('DLL01', 'BRS01');
6. 概念 IN 执行比 OR 快 - Page 46
7. 概念
The NOT operator negates the condition that follows it.
