背

java類：

public static void main(String[] a){}

Map、properties-->key, value
List、Linked-->順序
Set-->不重覆
Sorted、Tree-->排序
Hash-->雜物

oracle類：

INSERT INTO <table>(<many field>)VALUES(<many value>);
INSERT INTO <table> VALUES(<many value>);
INSERT INTO <table1> (<many field>) SELECT many field FROM <table2> WHERE...;

DELETE FROM <table>;

UPDATE <table_name> SET <column> = <value> WHERE...;

SELECT * FROM <table>;

CREATE TABLE <table> (
    <field> <type> [not null],
    CONSTRAINT <pk_name> PRIMARY KEY(<field>),
    CONSTRAINT <fk_name> FOREIGN KEY (<field>) REFERENCES <table>(<field>) [ON DELETE CASCADE]
);
CREATE SEQUENCE XXX_SEQUENCE
    INCREMENT BY 1  -- 每次加幾個
    START WITH 1    -- 從1開始計數
    NOMAXVALUE      -- 不設置最大值
    NOCYCLE         -- 一直累加，不循環
    CACHE 10;

XXX_SEQUENCE.NEXTVAL
XXX_SEQUENCE.CURRVAL

COMMENT ON TABLE <table> IS 'xxx';
COMMENT ON COLUMN <table>.<field> IS 'ooo';

ALTER TABLE <table> ADD <field> <type>;

ALTER TABLE <table> DROP COLUMN <field>;

ALTER TABLE <table> MODIFY <field> <type> [not null];--修改欄位，不包括重命名

ALTER TABLE <table> RENAME COLUMN <old_field> TO <new_field>;--重命名用這個


--看版本
SELECT * FROM V$VERSION;

--看所有表的comment SYS.USER_TAB_COMMENTS
--看所有欄的comment SYS.USER_COL_COMMENTS

--看所有表 SYS.USER_TABLES;

--某個表的某個欄包括ABC，只要知道有一張全表查詢的表叫USER_TAB_COLUMNS就夠了
SELECT * FROM SYS.USER_TAB_COLUMNS
WHERE TABLE_NAME = '<table>'
AND REGEXP_LIKE (COLUMN_NAME, '*ABC*');