Oracle Database 11g SQL 开发指南阅读记录
SQL语句分为5类
1. 查询语句 SELECT
2. 数据操纵语言（Data Manipulation Language, DML）语句
INSERT
UPDATE
DELETE
3. 数据定义语言（Data Definition Language, DDL）语句
CREATE
ALTER
DROP
RENAME
TRUNCATE
4. 事务控制（Transaction Control, TC）语句
COMMIT
ROLLBACK
SAVEPOINT
5. 数据控制语言（Data Control Language, DCL）语句
GRANT
REVOKE
SYSDATE
CREATE USE username IDENTIFIED BY password
GRANT CONNECT, RESOURCE TO username
id INTEGER CONSTRAINT student_pk PRIMARY KEY
CONSTRAINT ~~~ REFERENCES product_type(id)
CONSTRAINT compose_pk PRIMARY KEY (column1, column2)
TO_DATE('25-JUL-2007')+2 => 27-JUL-2007
连接操作符(||)
NVL(phone, 'Unknown phone number')
ANY = SOME where id > ANY(2, 3, 4) where id > ALL(2, 3, 4)
WHERE name LIKE '%\%%' ESCAPE '\'
LIKE, IN, BETWEEN, IS NULL, IS NAN, IS INFINITE
USING => ON (+)
_(一个) %(任意个)
AND 优先 OR
GROUP BY 可以不与HAVING字句一起使用，但是HAVING必须必须与GROUP BY字句一起使用。 GROUP BY分组，HAVING过滤。
SELECT product_type_id, AVG(price) FROM products WHERE price < 15 GROUP BY product_type_id HAVING AVG(price) > 13 ORDER BY AVG(price)
两种函数：单行函数（字符，数字，转换，日期，正则表达式）和聚合函数
TO_CHAR(dob, 'MONTH DD, YYYY') TO_DATE('7.4.07', 'MM.DD.YY')
ALTER SESSION SET NLS_DATE_FORMAT = 'MONTH-DD-YYYY';
ADD_MONTHS(x,y) LAST_DAY(x) MONTHS_BETWEEN(x, y) NEXT_DAY(x, day)
EXTRACT 取出年月日等。。
EXISTS性能高于IN
UNION ALL (包括重复的) UNION (不包括重复的) 类型必须一样，列数必须一样，名称可以不一样
INTERSECT MINUS
TRANSLATE(x, from_string, to_string)
DECODE(value, search_value, result, default_value) => CASE
SELECT division_id, SUM(salary) FROM employee GROUP BY ROLLUP(division_id) ORDER BY division_id;
SELECT division_id, SUM(salary) FROM employee GROUP BY ROLLUP(division_id, job_id) ORDER BY division_id;
任何聚合函数都可以和ROLLUP一起使用
SELECT division_id, SUM(salary) FROM employee GROUP BY CUBE(division_id, job_id) ORDER BY division_id;
GROUPING只能在使用ROLLUP或CUBE的查询时候使用
SELECT GROUPING(division_id), division_id, SUM(salary) FROM employee GROUP BY ROLLUP(division_id) ORDER BY division_id;
使用GROUPING SETS子句可以只返回小计记录
MERGE INTO products p
USING product_changes pc ON (
p.product_id = pc.product_id
)
WHEN MATCHED THEN
UPDATE
SET
p.product_type_id = pc.product_type_id,
p.name = pc.name,
p.description = pc.description,
p.price = pc.price
WHEN NOT MATCHED THEN
INSERT (
p.product_id, p.product_type_id, p.name, p.description, p.price
) VALUES (
pc.product_id, pc.product_type_id, pc.name, pc.description, pc.price
);
user_tables, user_tab_columns, all_tables, all_tab_columns;
ALTER TABLE salary_grades
ADD (average_salary AS ((low_salary + high_salary)/2));
ALTER TABLE order_status
DROP COLUMN modified_by;
ALTER TABLE order_status
ADD CONSTRAINT order_status_modified_by_fk
modified_by REFERENCES employee(employee_id) ON DELETE CASCADE;
ALTER TABLE order_status
ADD CONSTRAINT order_status_modified_by_fk
modified_by REFERENCES employee(employee_id) ON DELETE SET NULL;
ALTER TABLE order_status
ADD CONSTRAINT order_status_status_ck
CHECK (status in ('PLACED', 'PENDING', 'SHIPPED'));
ALTER TABLE order_status
DISABLE CONSTRAINT order_status_status_ck;
ALTER TABLE order_status
ENABLE CONSTRAINT order_status_status_ck;
ALTER TABLE order_status
ENABLE NOVALIDATE CONSTRAINT order_status_status_uq;
SET SERVEROUTPUT ON
DECLARE
v_product_id products.product_id%TYPE;
v_name products.name%TYPE;
v_price products.price%TYPE;
CURSOR v_product_cursor IS
SELECT product_id, name, price
FROM products
ORDER BY product_id;
BEGIN
OPEN v_product_cursor;
LOOP
FETCH v_product_cursor INTO v_product_id, name, price;
EXIT WHEN v_product_cursor%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(~~)
END LOOP;
CLOSE v_product_cursor;
END;
/
SET SERVEROUTPUT ON
DECLARE
CURSOR v_product_cursor IS
SELECT product_id, name, price
FROM products
ORDER BY product_id;
BEGIN
FOR v_product IN v_product_cursor LOOP
DBMS_OUTPUT.PUT_LINE(v_product.product_id || v_product.name || v_product.price)
END LOOP;
END;
/
Oracle预定义系统异常类型
| 命名的系统异常 |
产生原因 |
| ACCESS_INTO_NULL |
未定义对象 |
| CASE_NOT_FOUND |
CASE 中若未包含相应的 WHEN ，并且没有设置 ELSE 时 |
| COLLECTION_IS_NULL |
集合元素未初始化 |
| CURSER_ALREADY_OPEN |
游标已经打开 |
| DUP_VAL_ON_INDEX |
唯一索引对应的列上有重复的值 |
| INVALID_CURSOR |
在不合法的游标上进行操作 |
| INVALID_NUMBER |
内嵌的 SQL 语句不能将字符转换为数字 |
| NO_DATA_FOUND |
使用 select into 未返回行，或应用索引表未初始化的元素时 |
| TOO_MANY_ROWS |
执行 select into 时，结果集超过一行 |
| ZERO_DIVIDE |
除数为 0 |
| SUBSCRIPT_BEYOND_COUNT |
元素下标超过嵌套表或 VARRAY 的最大值 |
| SUBSCRIPT_OUTSIDE_LIMIT |
使用嵌套表或 VARRAY 时，将下标指定为负数 |
| VALUE_ERROR |
赋值时，变量长度不足以容纳实际数据 |
| LOGIN_DENIED |
PL/SQL 应用程序连接到 oracle 数据库时，提供了不正确的用户名或密码 |
| NOT_LOGGED_ON |
PL/SQL 应用程序在没有连接 oralce 数据库的情况下访问数据 |
| PROGRAM_ERROR |
PL/SQL 内部问题，可能需要重装数据字典＆ pl./SQL 系统包 |
| ROWTYPE_MISMATCH |
宿主游标变量与 PL/SQL 游标变量的返回类型不兼容 |
| SELF_IS_NULL |
使用对象类型时，在 null 对象上调用对象方法 |
| STORAGE_ERROR |
运行 PL/SQL 时，超出内存空间 |
| SYS_INVALID_ID |
无效的 ROWID 字符串 |
| TIMEOUT_ON_RESOURCE |
Oracle 在等待资源时超时 |
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