# 語言基礎 - 數據類型 integer 帶符號整數 real 浮點數 text 文本字符串 blob 輸入存儲 其他支出 int char - 運算符 == = != > >= < <= and or is等于 is not不等于 like %一個或多個 \_只有一個 in() not in() between 25 and 27 limit 3 offset 2 從第二個開始取三條數據 order by NAME desc, SALARY asc; 排序 exists() 子查詢 group by NAME having 條件 分組 select distinct 去重復 - 創建表,刪除表,插入數據,查找,更新 ``` <pre class="calibre14">``` DROP TABLE IF EXISTS <span class="token4">"t"</span><span class="token2">;</span> CREATE TABLE <span class="token4">"t"</span> <span class="token2">(</span> <span class="token4">"id"</span> integer NOT NULL PRIMARY KEY AUTOINCREMENT<span class="token2">,</span> <span class="token4">"ip"</span> <span class="token1">char</span><span class="token2">(</span><span class="token3">15</span><span class="token2">)</span> NOT NULL<span class="token2">,</span> <span class="token4">"money"</span> real NOT NULL <span class="token2">)</span><span class="token2">;</span> insert into <span class="token1">t</span><span class="token2">(</span>id<span class="token2">,</span>ip<span class="token2">,</span>money<span class="token2">)</span> <span class="token1">values</span><span class="token2">(</span><span class="token5">null</span><span class="token2">,</span><span class="token3">1</span><span class="token2">,</span><span class="token3">1.1</span><span class="token2">)</span> select <span class="token">*</span> from t update t set ip<span class="token">=</span><span class="token3">3</span> where id<span class="token">=</span><span class="token3">1</span> delete from t where id<span class="token">=</span><span class="token3">1</span> ``` ``` - 高級語句 ``` <pre class="calibre16">``` select <span class="token">*</span> from a cross join b 交叉連接 select <span class="token">*</span> from a inner join b on 條件 內連接 select <span class="token">*</span> from a left outer join b on 條件 左連接<span class="token2">,</span>不支持全鏈接右鏈接 select <span class="token">*</span> from a union select <span class="token">*</span> from b 合并結果<span class="token2">,</span>union all包括重復行 select ids id from table t<span class="token2">;</span>支持別名可以省略as create index i on <span class="token1">t</span><span class="token2">(</span>id<span class="token2">)</span> 單列索引 唯一索引 create unique index 不能重復數據 create index i on <span class="token1">t</span><span class="token2">(</span>id<span class="token2">,</span>id2<span class="token2">)</span> 組合索引 drop index i 刪除索引 alter table t rename to t1 重命名 alter table t add column id 添加列 不支持其他功能alter begin 開始事務 rollback 回滾 commit 提交事務 ``` ```