Sqlite3: Difference between revisions

Latest revision as of 01:08, 22 March 2017

Overview

Sqlite3 사용법 정리.

Commands

원문은 이곳<ref>https://www.sqlite.org/cli.html</ref>을 참조하자.

sqlite> .help
.backup ?DB? FILE      Backup DB (default "main") to FILE
.bail ON|OFF           Stop after hitting an error.  Default OFF
.databases             List names and files of attached databases
.dump ?TABLE? ...      Dump the database in an SQL text format
                         If TABLE specified, only dump tables matching
                         LIKE pattern TABLE.
.echo ON|OFF           Turn command echo on or off
.exit                  Exit this program
.explain ?ON|OFF?      Turn output mode suitable for EXPLAIN on or off.
                         With no args, it turns EXPLAIN on.
.header(s) ON|OFF      Turn display of headers on or off
.help                  Show this message
.import FILE TABLE     Import data from FILE into TABLE
.indices ?TABLE?       Show names of all indices
                         If TABLE specified, only show indices for tables
                         matching LIKE pattern TABLE.
.load FILE ?ENTRY?     Load an extension library
.log FILE|off          Turn logging on or off.  FILE can be stderr/stdout
.mode MODE ?TABLE?     Set output mode where MODE is one of:
                         csv      Comma-separated values
                         column   Left-aligned columns.  (See .width)
                         html     HTML <table> code
                         insert   SQL insert statements for TABLE
                         line     One value per line
                         list     Values delimited by .separator string
                         tabs     Tab-separated values
                         tcl      TCL list elements
.nullvalue STRING      Use STRING in place of NULL values
.open ?FILENAME?       Close existing database and reopen FILENAME
.output FILENAME       Send output to FILENAME
.output stdout         Send output to the screen
.print STRING...       Print literal STRING
.prompt MAIN CONTINUE  Replace the standard prompts
.quit                  Exit this program
.read FILENAME         Execute SQL in FILENAME
.restore ?DB? FILE     Restore content of DB (default "main") from FILE
.schema ?TABLE?        Show the CREATE statements
                         If TABLE specified, only show tables matching
                         LIKE pattern TABLE.
.separator STRING      Change separator used by output mode and .import
.show                  Show the current values for various settings
.stats ON|OFF          Turn stats on or off
.tables ?TABLE?        List names of tables
                         If TABLE specified, only list tables matching
                         LIKE pattern TABLE.
.timeout MS            Try opening locked tables for MS milliseconds
.trace FILE|off        Output each SQL statement as it is run
.vfsname ?AUX?         Print the name of the VFS stack
.width NUM1 NUM2 ...   Set column widths for "column" mode
.timer ON|OFF          Turn the CPU timer measurement on or off

.tables

현재의 데이터베이스에 있는 테이블 내용을 보여준다. 특정 테이블 이름을 같이 입력할 경우, 입력한 테이블이 데이터베이스에 존재하는지를 리턴한다.

sqlite> .tables
sample1  test   
sqlite> .tables test
test
sqlite> .tables test1
sqlite>

.schema

입력한 테이블의 상세 내용을 확인한다. 만약, 입력한 테이블 내용이 없을 경우, 해당 데이터베이스의 전체 테이블의 상세 내용을 출력한다.

sqlite> .schema test
CREATE TABLE test(seq integer PRIMARY KEY AUTOINCREMENT, test text);

sqlite> .schema
CREATE TABLE test(seq integer PRIMARY KEY AUTOINCREMENT, test text);
CREATE TABLE sample1(seq integer);

.headers

결과를 표시할 때, 헤더 정보를 표시할지 말지를 설정한다.

sqlite> .headers on
sqlite> select * from test;
seq|uniq_id
3926|ec1d7c92-83b0-4410-a6f4-897fc1522485

.mode

결과를 표시할 때, 어떤 방식으로 표시할 것인지를 설정한다.

.mode MODE ?TABLE?

다음의 표현방식 중 하나를 선택할 수 있다.

- csv - Comma-separated values
- column - Left-aligned columns.  (See .width)
- html - HTML <table> code
- insert - SQL insert statements for TABLE
- line - One value per line
- list - Values delimited by .separator string
- tabs - Tab-separated values
- tcl - TCL list elements

Datatypes

Strong classes and datatypes

Sqlite 에서는 크게 다음과 같은 분류로 데이터타입을 정의한다.

    NULL. The value is a NULL value.

    INTEGER. The value is a signed integer, stored in 1, 2, 3, 4, 6, or 8 bytes depending on the magnitude of the value.

    REAL. The value is a floating point value, stored as an 8-byte IEEE floating point number.

    TEXT. The value is a text string, stored using the database encoding (UTF-8, UTF-16BE or UTF-16LE).

    BLOB. The value is a blob of data, stored exactly as it was input.

Boolean Datatype

SQLite 에는 Boolean 타입을 위한 데이터 타입이 없다. 대신, integer 0(false), integer 1(true) 로 저장된다.

Date and Time Datatype

SQLite does not have a storage class set aside for storing dates and/or times. Instead, the built-in Date And Time Functions of SQLite are capable of storing dates and times as TEXT, REAL, or INTEGER values:

   TEXT as ISO8601 strings ("YYYY-MM-DD HH:MM:SS.SSS").
   REAL as Julian day numbers, the number of days since noon in Greenwich on November 24, 4714 B.C. according to the proleptic Gregorian calendar.
   INTEGER as Unix Time, the number of seconds since 1970-01-01 00:00:00 UTC.

Comparison expression

||
*    /    %
+    -
<<   >>   &    |
<    <=   >    >=
=    ==   !=   <>   IS   IS NOT   IN   LIKE   GLOB   MATCH   REGEXP
AND   
OR

Pragma

Sqlite3-pragma 항목 참조.

Statement

Basic

여러개의 SQL Statement 는 다음과 같이 구성된다.

그리고 각각의 SQL Statement 들은 다음과 같이 구성된다.

CREATE TABLE

Table 을 생성한다.

<source lang=sql> CREATE TABLE t(x INTEGER PRIMARY KEY ASC, y, z); CREATE TABLE t(x INTEGER, y, z, PRIMARY KEY(x ASC)); CREATE TABLE t(x INTEGER, y, z, PRIMARY KEY(x DESC)); </source>

CREATE VEIW

TABLE 에서 특정 데이터들만의 리스트를 구성하고자 할 때, VIEW 를 사용할 수 있다. 한번 VEIW 가 생성되면, SELECT 구문의 FROM 절로 사용될 수 있다<ref>https://www.sqlite.org/lang_createview.html</ref>.

SQLITE3의 VIEW는 오직 Read(SELECT) 만 가능하며, DELETE, INSERT, UPDATE 는 불가능하다. CREATE 와 VIEW 절 사이에 "TEMP" 혹은 "TEMPORARY" 를 사용할 수 있는데, 이걸 사용하게 되면 해당 커넥션이 연결되는 동안만 생성되고 유지되는 VIEW 를 생성하게 된다.

VIEW 는 굉장히 유용하면서도 SELECT 보다 약간이지만 더 나은 성능을 발휘한다<ref>http://stackoverflow.com/questions/9282325/sqlite3-views-affect-performance</ref>.

<source lang=sql> create view if not exists sms_active as select * from sms where on_going != 0; </source>

SELECT

INSERT/REPLACE

테이블에 데이터를 입력한다. <source lang=sql> INSERT INTO TABLE_NAME VALUES (value1,value2,value3,...valueN); </source>

Example

<source lang=sql> INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (5, 'David', 27, 'Texas', 85000.00 );

INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 );

INSERT OR REPLACE INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'New-York', 45000.00 ); </source>

UPDATE

테이블에 입력된 데이터를 갱신한다. <source lang=sql> UPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition]; </source>

<source lang=sql> UPDATE COMPANY SET ADDRESS = 'Texas' WHERE ID = 6; </source>

ALTER TABLE

테이블의 내용을 변경한다. <source lang=sql> ALTER TABLE database_name.table_name RENAME TO new_table_name; </source>

<source lang=sql> ALTER TABLE COMPANY RENAME TO OLD_COMPANY;

ALTER TABLE OLD_COMPANY ADD COLUMN SEX char(1); </source>

JOIN

CROSS JOIN

두 개의 <source lang=sql> sqlite> select dial_mode, type from ob_plan cross join ob_destination;

dial_mode|type 1|1 0|1 0|1 1|1 </source>

INNER JOIN

A INNER JOIN creates a new result table by combining column values of two tables(table1 and table2) based upon the join-predicate. The query compares each row of table1 with each row of table2 to find all pairs of rows which satisfy the join-oredicate. When the join-predicate is satisfied, column values for each matched pair of rows of A and B are combined into a result row.

OUTER JOIN

The OUTER JOIN is an extension of the INNER JOIN. Though SQL standard defines three types of OUTER JOINs(LEFT, RIGHT, FULL). But the SQLite only supports the LEFT OUTER JOIN. <source lang=sql>

</source>

Advanced

Attach

다른 데이터베이스 내용을 참조하고자 할 때 사용한다.

> attach /tmp/sqlite3/tmp.db as test;

EXPLAIN QUERY PLAN

Sqlite3 에서는 디버깅 및 High-level 디버깅을 을 위한 특수 Query를 지원한다. 이 Query를 이용하면 작성된 Query 가 정확히 어떤 Table/Index/View 등을 참조하는지 등의 정보를 확인할 수 있다.

결과값은 보통 다음의 4개의 컬럼으로 나온다. selectid, order, from 은 INTEGER 타입이고, 마지막 detail 은 TEXT 타입이다.

selectid, order, from, detail

<source lang=sql> sqlite> EXPLAIN QUERY PLAN select * from sms where on_going != 0; order|from|detail 0|0|TABLE sms

sqlite> EXPLAIN QUERY PLAN select * from sms where on_going < 0; order|from|detail 0|0|TABLE sms WITH INDEX sms_on_going </source>

Errors

unfinalized

sqlite3_close() 시, 다음과 같이 unfinalized 에러가 나올 경우, sqlite3_finalize() 를 호출해서 강제로 종료할 수 있다.

unable to close due to unfinalized statements or unfinished backups

http://stackoverflow.com/questions/373369/sqlite3unable-to-close-due-to-unfinalised-statements

References

Sqlite3: Difference between revisions

Latest revision as of 01:08, 22 March 2017

Contents

Overview

Commands

.tables

.schema

.headers

.mode

Datatypes

Strong classes and datatypes

Boolean Datatype

Date and Time Datatype

Comparison expression

Pragma

Statement

Basic

CREATE TABLE

CREATE VEIW

SELECT

INSERT/REPLACE

Example

UPDATE

ALTER TABLE

JOIN

CROSS JOIN

INNER JOIN

OUTER JOIN

Advanced

Attach

EXPLAIN QUERY PLAN

Errors

unfinalized

See also

References

Navigation menu

@@ Line 95: / Line 95: @@
 </pre>
 다음의 표현방식 중 하나를 선택할 수 있다.
-* csv - Comma-separated values
+<pre>
-* column - Left-aligned columns.  (See .width)
+- csv - Comma-separated values
-* html - HTML <table> code
+- column - Left-aligned columns.  (See .width)
-* insert - SQL insert statements for TABLE
+- html - HTML <table> code
-* line - One value per line
+- insert - SQL insert statements for TABLE
-* list - Values delimited by .separator string
+- line - One value per line
-* tabs - Tab-separated values
+- list - Values delimited by .separator string
-* tcl - TCL list elements
+- tabs - Tab-separated values
+- tcl - TCL list elements
+</pre>
 == Datatypes ==
 === Strong classes and datatypes ===
 Sqlite 에서는 크게 다음과 같은 분류로 데이터타입을 정의한다.
@@ Line 123: / Line 126: @@
 ==== Date and Time Datatype ====
 SQLite does not have a storage class set aside for storing dates and/or times. Instead, the built-in Date And Time Functions of SQLite are capable of storing dates and times as TEXT, REAL, or INTEGER values:
@@ Line 130: / Line 132: @@
      INTEGER as Unix Time, the number of seconds since 1970-01-01 00:00:00 UTC.
-== Pragma ==
+==== Comparison expression ====
-=== table_info() ===
-입력된 table 의 정보를 출력한다. 각각의 라인마다 테이블에 있는 모든 칼럼과 속성을 하나씩 출력한다. table 뿐만 아니라 view 정보도 확인할 수 있다. 각각의 항목별 내용은 아래 순서와 같다.
-* Index
-* Column name
-* Data type
-* Set NULL 가능 여부.(0:가능, 1:불가능)
-* Default value
-* Primary key 여부
 <pre>
-sqlite> pragma table_info(test);
+||
-|seq|integer|0||1
+*    /    %
-|uniq_id|text|1||0
++    -
+<<   >>   &    |
+<    <=   >    >=
+=    ==   !=   <>   IS   IS NOT   IN   LIKE   GLOB   MATCH   REGEXP
+AND
+OR
 </pre>
-== Attach ==
+== Pragma ==
-다른 데이터베이스 내용을 참조하고자 할 때 사용한다.
+[[Sqlite3-pragma]] 항목 참조.
-<pre>
-> attach /tmp/sqlite3/tmp.db as test;
+== Statement ==
-</pre>
+=== Basic ===
+여러개의 SQL Statement 는 다음과 같이 구성된다.
+[[File:Sql-stmt-list.gif|Right]]
+그리고 각각의 SQL Statement 들은 다음과 같이 구성된다.
+[[File:Sql-stmt.gif]]
+=== CREATE TABLE ===
+Table 을 생성한다.
+[[file:Create-table-stmt.gif]]
+<source lang=sql>
+CREATE TABLE t(x INTEGER PRIMARY KEY ASC, y, z);
+CREATE TABLE t(x INTEGER, y, z, PRIMARY KEY(x ASC));
+CREATE TABLE t(x INTEGER, y, z, PRIMARY KEY(x DESC));
+</source>
+=== CREATE VEIW ===
+TABLE 에서 특정 데이터들만의 리스트를 구성하고자 할 때, VIEW 를 사용할 수 있다. 한번 VEIW 가 생성되면, SELECT 구문의 FROM 절로 사용될 수 있다<ref>https://www.sqlite.org/lang_createview.html</ref>.
+SQLITE3의 VIEW는 오직 Read(SELECT) 만 가능하며, DELETE, INSERT, UPDATE 는 불가능하다. CREATE 와 VIEW 절 사이에 "TEMP" 혹은 "TEMPORARY" 를 사용할 수 있는데, 이걸 사용하게 되면 해당 커넥션이 연결되는 동안만 생성되고 유지되는 VIEW 를 생성하게 된다.
+VIEW 는 굉장히 유용하면서도 SELECT 보다 약간이지만 더 나은 성능을 발휘한다<ref>http://stackoverflow.com/questions/9282325/sqlite3-views-affect-performance</ref>.
+[[File:Create-view-stmt.gif]]
+<source lang=sql>
+create view if not exists sms_active as select * from sms where on_going != 0;
+</source>
+=== SELECT ===
+[[File:Select-stmt.gif]]
+=== INSERT/REPLACE ===
+테이블에 데이터를 입력한다.
+<source lang=sql>
+INSERT INTO TABLE_NAME VALUES (value1,value2,value3,...valueN);
+</source>
+[[File:Insert-stmt.gif]]
+==== Example ====
+<source lang=sql>
+INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (1, 'Paul', 32, 'California', 20000.00 );
+INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (2, 'Allen', 25, 'Texas', 15000.00 );
+INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );
+INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );
+INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (5, 'David', 27, 'Texas', 85000.00 );
+INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'South-Hall', 45000.00 );
+INSERT OR REPLACE INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) VALUES (6, 'Kim', 22, 'New-York', 45000.00 );
+</source>
+=== UPDATE ===
+테이블에 입력된 데이터를 갱신한다.
+<source lang=sql>
+UPDATE table_name SET column1 = value1, column2 = value2...., columnN = valueN WHERE [condition];
+</source>
+[[File:Update-stmt.gif]]
+<source lang=sql>
+UPDATE COMPANY SET ADDRESS = 'Texas' WHERE ID = 6;
+</source>
+=== ALTER TABLE ===
+테이블의 내용을 변경한다.
+<source lang=sql>
+ALTER TABLE database_name.table_name RENAME TO new_table_name;
+</source>
+[[File:Alter-table-stmt.gif]]
+<source lang=sql>
+ALTER TABLE COMPANY RENAME TO OLD_COMPANY;
+ALTER TABLE OLD_COMPANY ADD COLUMN SEX char(1);
+</source>
+=== JOIN ===
+==== CROSS JOIN ====
+두 개의
+<source lang=sql>
+sqlite> select dial_mode, type from ob_plan cross join ob_destination;
-== Example ==
+dial_mode|type
-Database 생성 후, 샘플 데이터를 입력한 뒤, 이를 프로그램을 통해 출력하는 예제를 작성해보자.
+|1
+|1
+|1
+|1
+</source>
-=== Create database ===
+==== INNER JOIN ====
+A INNER JOIN creates a new result table by combining column values of two tables(table1 and table2) based upon the join-predicate. The query compares each row of table1 with each row of table2 to find all pairs of rows which satisfy the join-oredicate. When the join-predicate is satisfied, column values for each matched pair of rows of A and B are combined into a result row.
 <pre>
-$ sqlite3 test.db
 </pre>
-<pre>
+==== OUTER JOIN ====
-sqlite> create table t1(
+The OUTER JOIN is an extension of the INNER JOIN. Though SQL standard defines three types of OUTER JOINs(LEFT, RIGHT, FULL). But the SQLite only supports the LEFT OUTER JOIN.
-   ...> id int
+<source lang=sql>
-   ...> id int primary key not null,
-   ...> name text not null,
-   ...> age int not null,
-   ...> address char(50),
-   ...> salary real
-   ...> );
-sqlite> .table
-t1
-sqlite> .schema t1
+</source>
-CREATE TABLE t1(
-id int primary key not null,
-name text not null,
-age int not null,
-address char(50),
-salary real
-);
-sqlite> insert into t1 (id, name, age, address, salary) values (1, "test_1", 10, "Somewhere in the earth", 10000);
+== Advanced ==
-sqlite> select * from t1;
+=== Attach ===
-|test_1|10|Somewhere in the earth|10000.0
+다른 데이터베이스 내용을 참조하고자 할 때 사용한다.
+<pre>
+> attach /tmp/sqlite3/tmp.db as test;
 </pre>
-=== Sample programs ===
+=== EXPLAIN QUERY PLAN ===
-<source lang=c>
+Sqlite3 에서는 디버깅 및 High-level 디버깅을 을 위한 특수 Query를 지원한다. 이 Query를 이용하면 작성된 Query 가 정확히 어떤 Table/Index/View 등을 참조하는지 등의 정보를 확인할 수 있다.
-/*
- * main.c
- *
- * Copyright 2015 sungtae kim <pchero@mywork>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
- * MA 02110-1301, USA.
- *
- *
- */
+결과값은 보통 다음의 4개의 컬럼으로 나온다. selectid, order, from 은 INTEGER 타입이고, 마지막 detail 은 TEXT 타입이다.
+<pre>
+selectid, order, from, detail
+</pre>
-#include <stdio.h>
+<source lang=sql>
-#include <sqlite3.h>
+sqlite> EXPLAIN QUERY PLAN select * from sms where on_going != 0;
+order|from|detail
+|0|TABLE sms
-static int callback(void *NotUsed, int argc, char **argv, char **azColName)
+sqlite> EXPLAIN QUERY PLAN select * from sms where on_going < 0;
-{
+order|from|detail
-	int i;
+|0|TABLE sms WITH INDEX sms_on_going
-	for(i = 0; i < argc; i++)
-	{
-		printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
-	}
-	printf("\n");
-	return 0;
-}
-int main(int argc, char **argv)
-{
-	sqlite3 *db;
-	char *zErrMsg = 0;
-	int rc;
-	if(argc != 3)
-	{
-		fprintf(stderr, "Usage: %s DATABASE SQL-STATEMENT\n", argv[0]);
-		return 1;
-	}
-	rc = sqlite3_open(argv[1], &db);
-	if(rc)
-	{
-		fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
-		sqlite3_close(db);
-		return(1);
-	}
-	rc = sqlite3_exec(db, argv[2], callback, 0, &zErrMsg);
-	if(rc != SQLITE_OK)
-	{
-		fprintf(stderr, "SQL_error: %s\n", zErrMsg);
-		sqlite3_free(zErrMsg);
-	}
-	sqlite3_close(db);
-	return 0;
-}
 </source>
+== Errors ==
+=== unfinalized ===
+sqlite3_close() 시, 다음과 같이 unfinalized 에러가 나올 경우, sqlite3_finalize() 를 호출해서 강제로 종료할 수 있다.
 <pre>
-$ gcc -o main main.c -lsqlite3
+unable to close due to unfinalized statements or unfinished backups
-$ ./main test.db "select * from t1"
-id = 1
-name = test_1
-age = 10
-address = Somewhere in the earth
-salary = 10000.0
 </pre>
+* http://stackoverflow.com/questions/373369/sqlite3unable-to-close-due-to-unfinalised-statements
 == See also ==
@@ Line 275: / Line 298: @@
 <references />
-[[category:linux]]
+[[category:sqlite3]]
-[[category:database]]

Sqlite3: Difference between revisions

Latest revision as of 01:08, 22 March 2017

Overview

Commands

.tables

.schema

.headers

.mode

Datatypes

Strong classes and datatypes

Boolean Datatype

Date and Time Datatype

Comparison expression

Pragma

Statement

Basic

CREATE TABLE

CREATE VEIW

SELECT

INSERT/REPLACE

Example

UPDATE

ALTER TABLE

JOIN

CROSS JOIN

INNER JOIN

OUTER JOIN

Advanced

Attach

EXPLAIN QUERY PLAN

Errors

unfinalized

See also

References

Navigation menu

Search