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SQLite 数据类型 和 基本命令

时间：2021-07-01 10:21:17 帮助过：23人阅读

SQLite 数据类型是一个用来指定任何对象的数据类型的属性。SQLite 中的每一列，每个变量和表达式都有相关的数据类型。

您可以在创建表的同时使用这些数据类型。SQLite 使用一个更普遍的动态类型系统。在 SQLite 中，值的数据类型与值本身是相关的，而不是与它的容器相关。

SQLite 存储类

每个存储在 SQLite 数据库中的值都具有以下存储类之一：

存储类描述
NULL 值是一个 NULL 值。
INTEGER 值是一个带符号的整数，根据值的大小存储在 1、2、3、4、6 或 8 字节中。
REAL 值是一个浮点值，存储为 8 字节的 IEEE 浮点数字。
TEXT 值是一个文本字符串，使用数据库编码（UTF-8、UTF-16BE 或 UTF-16LE）存储。
BLOB 值是一个 blob 数据，完全根据它的输入存储。

SQLite 的存储类稍微比数据类型更普遍。INTEGER 存储类，例如，包含 6 种不同的不同长度的整数数据类型。

SQLite 亲和(Affinity)类型

SQLite支持列的亲和类型概念。任何列仍然可以存储任何类型的数据，当数据插入时，该字段的数据将会优先采用亲缘类型作为该值的存储方式。SQLite目前的版本支持以下五种亲缘类型：

亲和类型描述
TEXT 数值型数据在被插入之前，需要先被转换为文本格式，之后再插入到目标字段中。
NUMERIC 当文本数据被插入到亲缘性为NUMERIC的字段中时，如果转换操作不会导致数据信息丢失以及完全可逆，那么SQLite就会将该文本数据转换为INTEGER或REAL类型的数据，如果转换失败，SQLite仍会以TEXT方式存储该数据。对于NULL或BLOB类型的新数据，SQLite将不做任何转换，直接以NULL或BLOB的方式存储该数据。需要额外说明的是，对于浮点格式的常量文本，如"30000.0"，如果该值可以转换为INTEGER同时又不会丢失数值信息，那么SQLite就会将其转换为INTEGER的存储方式。
INTEGER 对于亲缘类型为INTEGER的字段，其规则等同于NUMERIC，唯一差别是在执行CAST表达式时。
REAL 其规则基本等同于NUMERIC，唯一的差别是不会将"30000.0"这样的文本数据转换为INTEGER存储方式。
NONE 不做任何的转换，直接以该数据所属的数据类型进行存储。　　

SQLite 亲和类型(Affinity)及类型名称

下表列出了当创建 SQLite3 表时可使用的各种数据类型名称，同时也显示了相应的亲和类型：

数据类型亲和类型

  • INT

  • INTEGER

  • TINYINT

  • SMALLINT

  • MEDIUMINT

  • BIGINT

  • UNSIGNED BIG INT

  • INT2

  • INT8

 INTEGER

  • CHARACTER(20)

  • VARCHAR(255)

  • VARYING CHARACTER(255)

  • NCHAR(55)

  • NATIVE CHARACTER(70)

  • NVARCHAR(100)

  • TEXT

  • CLOB

 TEXT

  • BLOB

  • no datatype specified

 NONE

  • REAL

  • DOUBLE

  • DOUBLE PRECISION

  • FLOAT

 REAL

  • NUMERIC

  • DECIMAL(10,5)

  • BOOLEAN

  • DATE

  • DATETIME

 NUMERIC

Boolean 数据类型

SQLite 没有单独的 Boolean 存储类。相反，布尔值被存储为整数 0（false）和 1（true）。

BLOB 和 MEMO 的区别

SQLite 中 BLOB 类型的字段，可以存储任何二进制内容，而MEMO类型的字段，可以存储任意长度的普通文本。

Date 与 Time 数据类型

SQLite 没有一个单独的用于存储日期和/或时间的存储类，但 SQLite 能够把日期和时间存储为 TEXT、REAL 或 INTEGER 值。

存储类日期格式
TEXT 格式为 "YYYY-MM-DD HH:MM:SS.SSS" 的日期。
REAL 从公元前 4714 年 11 月 24 日格林尼治时间的正午开始算起的天数。
INTEGER 从 1970-01-01 00:00:00 UTC 算起的秒数。

您可以以任何上述格式来存储日期和时间，并且可以使用内置的日期和时间函数来自由转换不同格式。

 

技术图片

 

 

SQLite 语法

SQLite 是遵循一套独特的称为语法的规则和准则。本教程列出了所有基本的 SQLite 语法，向您提供了一个 SQLite 快速入门。

大小写敏感性

有个重要的点值得注意，SQLite 是不区分大小写的，但也有一些命令是大小写敏感的，比如 GLOB 和 glob 在 SQLite 的语句中有不同的含义。

注释

SQLite 注释是附加的注释，可以在 SQLite 代码中添加注释以增加其可读性，他们可以出现在任何空白处，包括在表达式内和其他 SQL 语句的中间，但它们不能嵌套。

SQL 注释以两个连续的 "-" 字符（ASCII 0x2d）开始，并扩展至下一个换行符（ASCII 0x0a）或直到输入结束，以先到者为准。

您也可以使用 C 风格的注释，以 "/*" 开始，并扩展至下一个 "*/" 字符对或直到输入结束，以先到者为准。SQLite的注释可以跨越多行。

  1. <span class="pln">sqlite<span class="pun">>.<span class="pln">help <span class="pun">--<span class="pln"> <span class="pun">这是一个简单的注释</span></span></span></span></span></span>

SQLite 语句

所有的 SQLite 语句可以以任何关键字开始，如 SELECT、INSERT、UPDATE、DELETE、ALTER、DROP 等，所有的语句以分号（;）结束。

SQLite ANALYZE 语句：

  1. <span class="pln">ANALYZE<span class="pun">;<span class="pln">
  2. <span class="kwd">or<span class="pln">
  3. ANALYZE database_name<span class="pun">;<span class="pln">
  4. <span class="kwd">or<span class="pln">
  5. ANALYZE database_name<span class="pun">.<span class="pln">table_name<span class="pun">;</span></span></span></span></span></span></span></span></span></span></span></span>

SQLite AND/OR 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  CONDITION<span class="pun">-<span class="lit">1<span class="pln"> <span class="pun">{<span class="pln">AND<span class="pun">|<span class="pln">OR<span class="pun">}<span class="pln"> CONDITION<span class="pun">-<span class="lit">2<span class="pun">;</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite ALTER TABLE 语句：

  1. <span class="pln">ALTER TABLE table_name ADD COLUMN column_def<span class="pun">...;</span></span>

SQLite ALTER TABLE 语句（Rename）：

  1. <span class="pln">ALTER TABLE table_name RENAME TO new_table_name<span class="pun">;</span></span>

SQLite ATTACH DATABASE 语句：

  1. <span class="pln">ATTACH DATABASE <span class="str">‘DatabaseName‘<span class="pln"> <span class="typ">As<span class="pln"> <span class="str">‘Alias-Name‘<span class="pun">;</span></span></span></span></span></span></span>

SQLite BEGIN TRANSACTION 语句：

  1. <span class="kwd">BEGIN<span class="pun">;<span class="pln">
  2. <span class="kwd">or<span class="pln">
  3. <span class="kwd">BEGIN<span class="pln"> EXCLUSIVE TRANSACTION<span class="pun">;</span></span></span></span></span></span></span></span>

SQLite BETWEEN 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  column_name BETWEEN val<span class="pun">-<span class="lit">1<span class="pln"> AND val<span class="pun">-<span class="lit">2<span class="pun">;</span></span></span></span></span></span></span></span></span></span></span>

SQLite COMMIT 语句：

  1. <span class="pln">COMMIT<span class="pun">;</span></span>

SQLite CREATE INDEX 语句：

  1. <span class="pln">CREATE INDEX index_name
  2. ON table_name <span class="pun">(<span class="pln"> column_name COLLATE NOCASE <span class="pun">);</span></span></span></span>

SQLite CREATE UNIQUE INDEX 语句：

  1. <span class="pln">CREATE UNIQUE INDEX index_name
  2. ON table_name <span class="pun">(<span class="pln"> column1<span class="pun">,<span class="pln"> column2<span class="pun">,...<span class="pln">columnN<span class="pun">);</span></span></span></span></span></span></span></span>

SQLite CREATE TABLE 语句：

  1. <span class="pln">CREATE TABLE table_name<span class="pun">(<span class="pln">
  2.    column1 datatype<span class="pun">,<span class="pln">
  3.    column2 datatype<span class="pun">,<span class="pln">
  4.    column3 datatype<span class="pun">,<span class="pln">
  5.    <span class="pun">.....<span class="pln">
  6.    columnN datatype<span class="pun">,<span class="pln">
  7.    PRIMARY KEY<span class="pun">(<span class="pln"> one <span class="kwd">or<span class="pln"> more columns <span class="pun">)<span class="pln">
  8. <span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite CREATE TRIGGER 语句：

  1. <span class="pln">CREATE TRIGGER database_name<span class="pun">.<span class="pln">trigger_name 
  2. BEFORE INSERT ON table_name FOR EACH ROW
  3. <span class="kwd">BEGIN<span class="pln"> 
  4.    stmt1<span class="pun">;<span class="pln"> 
  5.    stmt2<span class="pun">;<span class="pln">
  6.    <span class="pun">....<span class="pln">
  7. <span class="kwd">END<span class="pun">;</span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite CREATE VIEW 语句：

  1. <span class="pln">CREATE VIEW database_name<span class="pun">.<span class="pln">view_name  AS
  2. SELECT statement<span class="pun">....;</span></span></span></span>

SQLite CREATE VIRTUAL TABLE 语句：

  1. <span class="pln">CREATE VIRTUAL TABLE database_name<span class="pun">.<span class="pln">table_name USING weblog<span class="pun">(<span class="pln"> access<span class="pun">.<span class="pln">log <span class="pun">);<span class="pln">
  2. <span class="kwd">or<span class="pln">
  3. CREATE VIRTUAL TABLE database_name<span class="pun">.<span class="pln">table_name USING fts3<span class="pun">(<span class="pln"> <span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite COMMIT TRANSACTION 语句：

  1. <span class="pln">COMMIT<span class="pun">;</span></span>

SQLite COUNT 子句：

  1. <span class="pln">SELECT COUNT<span class="pun">(<span class="pln">column_name<span class="pun">)<span class="pln">
  2. FROM   table_name
  3. WHERE  CONDITION<span class="pun">;</span></span></span></span></span></span>

SQLite DELETE 语句：

  1. <span class="pln">DELETE FROM table_name
  2. WHERE  <span class="pun">{<span class="pln">CONDITION<span class="pun">};</span></span></span></span>

SQLite DETACH DATABASE 语句：

  1. <span class="pln">DETACH DATABASE <span class="str">‘Alias-Name‘<span class="pun">;</span></span></span>

SQLite DISTINCT 子句：

  1. <span class="pln">SELECT DISTINCT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name<span class="pun">;</span></span></span></span></span></span>

SQLite DROP INDEX 语句：

  1. <span class="pln">DROP INDEX database_name<span class="pun">.<span class="pln">index_name<span class="pun">;</span></span></span></span>

SQLite DROP TABLE 语句：

  1. <span class="pln">DROP TABLE database_name<span class="pun">.<span class="pln">table_name<span class="pun">;</span></span></span></span>

SQLite DROP VIEW 语句：

  1. <span class="pln">DROP VIEW view_name<span class="pun">;</span></span>

SQLite DROP TRIGGER 语句：

  1. <span class="pln">DROP TRIGGER trigger_name</span>

SQLite EXISTS 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  column_name EXISTS <span class="pun">(<span class="pln">SELECT <span class="pun">*<span class="pln"> FROM   table_name <span class="pun">);</span></span></span></span></span></span></span></span></span></span>

SQLite EXPLAIN 语句：

  1. <span class="pln">EXPLAIN INSERT statement<span class="pun">...;<span class="pln">
  2. <span class="kwd">or<span class="pln"> 
  3. EXPLAIN QUERY PLAN SELECT statement<span class="pun">...;</span></span></span></span></span></span>

SQLite GLOB 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  column_name GLOB <span class="pun">{<span class="pln"> PATTERN <span class="pun">};</span></span></span></span></span></span></span></span>

SQLite GROUP BY 子句：

  1. <span class="pln">SELECT SUM<span class="pun">(<span class="pln">column_name<span class="pun">)<span class="pln">
  2. FROM   table_name
  3. WHERE  CONDITION
  4. GROUP BY column_name<span class="pun">;</span></span></span></span></span></span>

SQLite HAVING 子句：

  1. <span class="pln">SELECT SUM<span class="pun">(<span class="pln">column_name<span class="pun">)<span class="pln">
  2. FROM   table_name
  3. WHERE  CONDITION
  4. GROUP BY column_name
  5. HAVING <span class="pun">(<span class="pln">arithematic <span class="kwd">function<span class="pln"> condition<span class="pun">);</span></span></span></span></span></span></span></span></span></span>

SQLite INSERT INTO 语句：

  1. <span class="pln">INSERT INTO table_name<span class="pun">(<span class="pln"> column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN<span class="pun">)<span class="pln">
  2. VALUES <span class="pun">(<span class="pln"> value1<span class="pun">,<span class="pln"> value2<span class="pun">....<span class="pln">valueN<span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite IN 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  column_name IN <span class="pun">(<span class="pln">val<span class="pun">-<span class="lit">1<span class="pun">,<span class="pln"> val<span class="pun">-<span class="lit">2<span class="pun">,...<span class="pln">val<span class="pun">-<span class="pln">N<span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite Like 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  column_name LIKE <span class="pun">{<span class="pln"> PATTERN <span class="pun">};</span></span></span></span></span></span></span></span>

SQLite NOT IN 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  column_name NOT IN <span class="pun">(<span class="pln">val<span class="pun">-<span class="lit">1<span class="pun">,<span class="pln"> val<span class="pun">-<span class="lit">2<span class="pun">,...<span class="pln">val<span class="pun">-<span class="pln">N<span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite ORDER BY 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  CONDITION
  4. ORDER BY column_name <span class="pun">{<span class="pln">ASC<span class="pun">|<span class="pln">DESC<span class="pun">};</span></span></span></span></span></span></span></span></span></span>

SQLite PRAGMA 语句：

  1. <span class="pln">PRAGMA pragma_name<span class="pun">;<span class="pln">
  2. <span class="typ">For<span class="pln"> example<span class="pun">:<span class="pln">
  3. PRAGMA page_size<span class="pun">;<span class="pln">
  4. PRAGMA cache_size <span class="pun">=<span class="pln"> <span class="lit">1024<span class="pun">;<span class="pln">
  5. PRAGMA table_info<span class="pun">(<span class="pln">table_name<span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite RELEASE SAVEPOINT 语句：

  1. <span class="pln">RELEASE savepoint_name<span class="pun">;</span></span>

SQLite REINDEX 语句：

  1. <span class="pln">REINDEX collation_name<span class="pun">;<span class="pln">
  2. REINDEX database_name<span class="pun">.<span class="pln">index_name<span class="pun">;<span class="pln">
  3. REINDEX database_name<span class="pun">.<span class="pln">table_name<span class="pun">;</span></span></span></span></span></span></span></span></span></span>

SQLite ROLLBACK 语句：

  1. <span class="pln">ROLLBACK<span class="pun">;<span class="pln">
  2. <span class="kwd">or<span class="pln">
  3. ROLLBACK TO SAVEPOINT savepoint_name<span class="pun">;</span></span></span></span></span></span>

SQLite SAVEPOINT 语句：

  1. <span class="pln">SAVEPOINT savepoint_name<span class="pun">;</span></span>

SQLite SELECT 语句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name<span class="pun">;</span></span></span></span></span></span>

SQLite UPDATE 语句：

  1. <span class="pln">UPDATE table_name
  2. SET column1 <span class="pun">=<span class="pln"> value1<span class="pun">,<span class="pln"> column2 <span class="pun">=<span class="pln"> value2<span class="pun">....<span class="pln">columnN<span class="pun">=<span class="pln">valueN
  3. <span class="pun">[<span class="pln"> WHERE  CONDITION <span class="pun">];</span></span></span></span></span></span></span></span></span></span></span></span></span></span>

SQLite VACUUM 语句：

  1. <span class="pln">VACUUM<span class="pun">;</span></span>

SQLite WHERE 子句：

  1. <span class="pln">SELECT column1<span class="pun">,<span class="pln"> column2<span class="pun">....<span class="pln">columnN
  2. FROM   table_name
  3. WHERE  CONDITION<span class="pun">;</span></span></span></span></span></span>

 

SQLite 命令

本章将向您讲解 SQLite 编程人员所使用的简单却有用的命令。这些命令被称为 SQLite 的点命令，这些命令的不同之处在于它们不以分号 ; 结束。

让我们在命令提示符下键入一个简单的 sqlite3 命令，在 SQLite 命令提示符下，您可以使用各种 SQLite 命令。

  1. <span class="pln">$ sqlite3
  2. <span class="typ">SQLite<span class="pln"> version <span class="lit">3.3<span class="pun">.<span class="lit">6<span class="pln">
  3. <span class="typ">Enter<span class="pln"> <span class="str">".help"<span class="pln"> <span class="kwd">for<span class="pln"> instructions
  4. sqlite<span class="pun">></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

如需获取可用的点命令的清单，可以在任何时候输入 ".help"。例如：

  1. <span class="pln">sqlite<span class="pun">>.<span class="pln">help</span></span></span>

上面的命令会显示各种重要的 SQLite 点命令的列表，如下所示：

命令描述
.backup ?DB? FILE 备份 DB 数据库（默认是 "main"）到 FILE 文件。
.bail ON|OFF 发生错误后停止。默认为 OFF。
.databases 列出数据库的名称及其所依附的文件。
.dump ?TABLE? 以 SQL 文本格式转储数据库。如果指定了 TABLE 表，则只转储匹配 LIKE 模式的 TABLE 表。
.echo ON|OFF 开启或关闭 echo 命令。
.exit 退出 SQLite 提示符。
.explain ON|OFF 开启或关闭适合于 EXPLAIN 的输出模式。如果没有带参数，则为 EXPLAIN on，即开启 EXPLAIN。
.header(s) ON|OFF 开启或关闭头部显示。
.help 显示消息。
.import FILE TABLE 导入来自 FILE 文件的数据到 TABLE 表中。
.indices ?TABLE? 显示所有索引的名称。如果指定了 TABLE 表，则只显示匹配 LIKE 模式的 TABLE 表的索引。
.load FILE ?ENTRY? 加载一个扩展库。
.log FILE|off 开启或关闭日志。FILE 文件可以是 stderr（标准错误）/stdout（标准输出）。
.mode MODE 设置输出模式，MODE 可以是下列之一：

  • csv 逗号分隔的值

  • column 左对齐的列

  • html HTML 的 <table> 代码

  • insert TABLE 表的 SQL 插入（insert）语句

  • line 每行一个值

  • list 由 .separator 字符串分隔的值

  • tabs 由 Tab 分隔的值

  • tcl TCL 列表元素
.nullvalue STRING 在 NULL 值的地方输出 STRING 字符串。
.output FILENAME 发送输出到 FILENAME 文件。
.output stdout 发送输出到屏幕。
.print STRING... 逐字地输出 STRING 字符串。
.prompt MAIN CONTINUE 替换标准提示符。
.quit 退出 SQLite 提示符。
.read FILENAME 执行 FILENAME 文件中的 SQL。
.schema ?TABLE? 显示 CREATE 语句。如果指定了 TABLE 表，则只显示匹配 LIKE 模式的 TABLE 表。
.separator STRING 改变输出模式和 .import 所使用的分隔符。
.show 显示各种设置的当前值。
.stats ON|OFF 开启或关闭统计。
.tables ?PATTERN? 列出匹配 LIKE 模式的表的名称。
.timeout MS 尝试打开锁定的表 MS 毫秒。
.width NUM NUM 为 "column" 模式设置列宽度。
.timer ON|OFF 开启或关闭 CPU 定时器。

让我们尝试使用 .show 命令，来查看 SQLite 命令提示符的默认设置。

  1. <span class="pln">sqlite<span class="pun">>.<span class="pln">show
  2.      echo<span class="pun">:<span class="pln"> off
  3.   explain<span class="pun">:<span class="pln"> off
  4.   headers<span class="pun">:<span class="pln"> off
  5.      mode<span class="pun">:<span class="pln"> column
  6. nullvalue<span class="pun">:<span class="pln"> <span class="str">""<span class="pln">
  7.    output<span class="pun">:<span class="pln"> stdout
  8. separator<span class="pun">:<span class="pln"> <span class="str">"|"<span class="pln">
  9.     width<span class="pun">:<span class="pln">
  10. sqlite<span class="pun">></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
确保 sqlite> 提示符与点命令之间没有空格，否则将无法正常工作。

格式化输出

您可以使用下列的点命令来格式化输出为本教程下面所列出的格式：

  1. <span class="pln">sqlite<span class="pun">>.<span class="pln">header on
  2. sqlite<span class="pun">>.<span class="pln">mode column
  3. sqlite<span class="pun">>.<span class="pln">timer on
  4. sqlite<span class="pun">></span></span></span></span></span></span></span></span>

上面设置将产生如下格式的输出：

  1. <span class="pln">ID          NAME        AGE         ADDRESS     SALARY
  2. <span class="pun">----------<span class="pln">  <span class="pun">----------<span class="pln">  <span class="pun">----------<span class="pln">  <span class="pun">----------<span class="pln">  <span class="pun">----------<span class="pln">
  3. <span class="lit">1<span class="pln">           <span class="typ">Paul<span class="pln">        <span class="lit">32<span class="pln">          <span class="typ">California<span class="pln">  <span class="lit">20000.0<span class="pln">
  4. <span class="lit">2<span class="pln">           <span class="typ">Allen<span class="pln">       <span class="lit">25<span class="pln">          <span class="typ">Texas<span class="pln">       <span class="lit">15000.0<span class="pln">
  5. <span class="lit">3<span class="pln">           <span class="typ">Teddy<span class="pln">       <span class="lit">23<span class="pln">          <span class="typ">Norway<span class="pln">      <span class="lit">20000.0<span class="pln">
  6. <span class="lit">4<span class="pln">           <span class="typ">Mark<span class="pln">        <span class="lit">25<span class="pln">          <span class="typ">Rich<span class="pun">-<span class="typ">Mond<span class="pln">   <span class="lit">65000.0<span class="pln">
  7. <span class="lit">5<span class="pln">           <span class="typ">David<span class="pln">       <span class="lit">27<span class="pln">          <span class="typ">Texas<span class="pln">       <span class="lit">85000.0<span class="pln">
  8. <span class="lit">6<span class="pln">           <span class="typ">Kim<span class="pln">         <span class="lit">22<span class="pln">          <span class="typ">South<span class="pun">-<span class="typ">Hall<span class="pln">  <span class="lit">45000.0<span class="pln">
  9. <span class="lit">7<span class="pln">           <span class="typ">James<span class="pln">       <span class="lit">24<span class="pln">          <span class="typ">Houston<span class="pln">     <span class="lit">10000.0<span class="pln">
  10. CPU <span class="typ">Time<span class="pun">:<span class="pln"> user <span class="lit">0.000000<span class="pln"> sys <span class="lit">0.000000</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>

sqlite_master 表格

主表中保存数据库表的关键信息，并把它命名为 sqlite_master。如要查看表概要，可按如下操作：

  1. <span class="pln">sqlite<span class="pun">>.<span class="pln">schema sqlite_master</span></span></span>

这将产生如下结果：

  1. <span class="pln">CREATE TABLE sqlite_master <span class="pun">(<span class="pln">
  2.   type text<span class="pun">,<span class="pln">
  3.   name text<span class="pun">,<span class="pln">
  4.   tbl_name text<span class="pun">,<span class="pln">
  5.   rootpage integer<span class="pun">,<span class="pln">
  6.   sql text
  7. <span class="pun">);</span></span></span></span></span></span></span></span></span></span></span></span>

 

============== End

 

SQLite 数据类型 和 基本命令

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