Difference between revisions of "Search an SQL database using sqlite3"
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</syntaxhighlight> | </syntaxhighlight> | ||
=== Displaying tables and columns === | |||
You can then display tables with: | You can then display tables with: | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
=== Getting a list of column names === | |||
An alternative way to get a list of column names not mentioned here that is cross platform and does not rely on the sqlite3.exe shell is to select from the <code>PRAGMA_TABLE_INFO()</code> table value function. | An alternative way to get a list of column names not mentioned here that is cross platform and does not rely on the sqlite3.exe shell is to select from the <code>PRAGMA_TABLE_INFO()</code> table value function. | ||
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rootpage | rootpage | ||
sql | sql | ||
</syntaxhighlight> | |||
You can check if a certain column exists by querying: | You can check if a certain column exists by querying: | ||
<syntaxhighlight lang="SQL" line> | |||
SELECT 1 FROM PRAGMA_TABLE_INFO('your_table') WHERE name='column1'; | SELECT 1 FROM PRAGMA_TABLE_INFO('your_table') WHERE name='column1'; | ||
1 | 1 |
Revision as of 16:55, 14 November 2021
https://www.sqlite.org/index.html
sqlite
implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine to query .sql
files.
Getting started
To use sqlite, you must have a valid metadata file with a .db
file extension, and an installed version of SQL. This tutorial assumes knowledge of the command line.
To start the sql engine, type:
sqlite3
The prompt will change, showing that the sqlite engine has been initialised. To open a metadata file, type:
.open filename.db
Displaying tables and columns
You can then display tables with:
.tables
Based on what is returned, you can then query the content of each table with commands such as:
SELECT * FROM mytable;
You may want to have a more human-readable view of the data that is printed in the terminal, by organising the headings and columns:
.headers ON
.mode column
You will get output like:
.headers on
.mode column
select * from mytable;
id foo bar
---------- ---------- ----------
1 val1 val2
2 val3 val4
Getting a list of column names
An alternative way to get a list of column names not mentioned here that is cross platform and does not rely on the sqlite3.exe shell is to select from the PRAGMA_TABLE_INFO()
table value function.
SELECT name FROM PRAGMA_TABLE_INFO('your_table');
name
tbl_name
rootpage
sql
You can check if a certain column exists by querying:
SELECT 1 FROM PRAGMA_TABLE_INFO('your_table') WHERE name='column1';
1