How to get a list of column names on Sqlite3 database?

Question

I want to migrate my iPhone app to a new database version. Since I don't have some version saved, I need to check if certain column names exist.

This Stackoverflow entry suggests doing the select

SELECT sql FROM sqlite_master
WHERE tbl_name = 'table_name' AND type = 'table'

and parse the result.

Is that the common way? Alternatives?

• Suragch: For the specific case of SQLite.swift, see this question and answer for a simple list of column names or this one for migration issues.
• Owen Pauling: Possible duplicate of How to get a list of column names

Answer 1

PRAGMA table_info(table_name);

will get you a list of all the column names.

• Jason: but you can't select from that table. It's just plain annoying. I'm trying something like this... but it don't work create temporary table TmpCols (cid integer, name text, type text, nn bit, dflt_value, pk bit); .mode insert TmpCols .output cols PRAGMA TABLE_INFO('yourtable'); .read cols .mode csv .output stdout
• Noumenon: Just to put this into code terms for SQLiteDatabase on Android, write db.rawQuery("PRAGMA table_info(" + tablename + ")", null);
• user1032317: This will also work in case of View. PRAGMA table_info(View_Name); This will list all columns of a View
• rassa45: Why is it called a Pragma? Aren't those used to hack the compiler? Wtf is it doing here lol?
• mdisibio: To execute as a query, see answer from @user1461607: select * from pragma_table_info('tblName') as tblInfo;

Answer 2

If you do

.headers ON

you will get the desired result.

• eastwater: how to align up headers with content below?
• ruffin: And to always have that on, put it in your .sqliterc file.
• Christopher Pisz: Should this work with an empty table? I am still not seeing column names
• user3768495: For some reasons I don't know, the PRAGMA method and the .schema method both didn't work for me. But this one works just fine.
• brother-bilo: .headers on and .mode columns will turn on columns names and align everything

Answer 3

If you have the sqlite database, use the sqlite3 command line program and these commands:

To list all the tables in the database:

.tables

To show the schema for a given tablename:

.schema tablename

• Nick Tomlin: Although the output isn't as "readable" (perhaps) this is_much_ easier to remember than PRAGMA table_info(table_name);
• Michael: @NickTomlin Unfortunately, this method requires having the sqlite3 command line program, as dot commands are not valid SQL.

Answer 4

Just for super noobs like me wondering how or what people meant by

PRAGMA table_info('table_name') 

You want to use use that as your prepare statement as shown below. Doing so selects a table that looks like this except is populated with values pertaining to your table.

cid name type notnull dflt_value pk 
---------- ---------- ---------- ---------- ---------- ----------
0 id integer 99 1 
1 name 0 0

Where id and name are the actual names of your columns. So to get that value you need to select column name by using:

//returns the name
sqlite3_column_text(stmt, 1);
//returns the type
sqlite3_column_text(stmt, 2);

Which will return the current row's column's name. To grab them all or find the one you want you need to iterate through all the rows. Simplest way to do so would be in the manner below.

//where rc is an int variable if wondering :/
rc = sqlite3_prepare_v2(dbPointer, "pragma table_info ('your table name goes here')", -1, &stmt, NULL);
if (rc==SQLITE_OK)
{
 //will continue to go down the rows (columns in your table) till there are no more
 while(sqlite3_step(stmt) == SQLITE_ROW)
 {
 sprintf(colName, "%s", sqlite3_column_text(stmt, 1));
 //do something with colName because it contains the column's name
 }
}

• xeruf: What they meant by that is to execute sqlite3 (or whatever it is named for you) to go into the sqlite CLI and then type in that text. No need to write extensive code for that :)
• Mike Williamson: Yes, as @Xerus says... no need for extensive code. Just use sqlite3 directly. Also, @birdbuster, it helps to specify the language and library you are using. It looks to me like C++ (from the sprintf function). It is helpful to clarify, since the OP question was language-agnostic.

Answer 5

If you want the output of your queries to include columns names and be correctly aligned as columns, use these commands in sqlite3:

.headers on
.mode column

You will get output like:

sqlite> .headers on
sqlite> .mode column
sqlite> select * from mytable;
id foo bar
---------- ---------- ----------
1 val1 val2
2 val3 val4

• Daniel Lidström: And put those in ~/.sqliterc.
• Ash: All terminal commands an no SQL.

Answer 6

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

This is what you use if you don't want to parse the result of select sql from sqlite_master or pragma table_info.

Note this feature is experimental and was added in SQLite version 3.16.0 (2017年01月02日).

Reference:

https://www.sqlite.org/pragma.html#pragfunc

• Jinghui Niu: This only works for local db. if you try this with attached schemas, it won't work.
• user1461607: @JinghuiNiu It works if you pass the schema as the second argument, pragma_table_info('table', 'schema').
• Ghulam: This is the best / accurate way to retrieve column names ONLY.

Answer 7

To get a list of columns you can simply use:

.schema tablename

• RajeshM: This will not show columns added with the ALTER statement.

Answer 8

I know it is an old thread, but recently I needed the same and found a neat way:

SELECT c.name FROM pragma_table_info('your_table_name') c;

• Luuk: You did mean: where t.name = 'table';
• user1461607: did you find the neat way from my answer? 😂
• Gregg Burns: I think the c has him confused. Gonna be a long journey for this one.
• U. Windl: The answer could need an explanation: After all it should be an answer, and not a "guess what this code does" riddle.
• Hilton Fernandes: Great answer, Slavian ! Thank you

Answer 9

These commands below can set column names:

.headers on

.header on

Then, you can get the result with column names as shown below:

sqlite> SELECT * FROM user;
id|first_name|last_name|age
1|Steve|Jobs|56
2|Bill|Gates|66
3|Mark|Zuckerberg|38

And, these commands below can unset column names:

.headers off

.header off

Then, you can get the result without column names as shown below:

sqlite> SELECT * FROM user;
1|Steve|Jobs|56
2|Bill|Gates|66
3|Mark|Zuckerberg|38

And, these commands below can show the details of the command .headers:

.help .headers

.help .header

.help headers

.help header

Then, you can show the details of the command .headers as shown below:

sqlite> .help .headers
.headers on|off Turn display of headers on or off

In addition, this command below can set the output mode box:

.mode box

Then, you can set the output mode box as shown below:

sqlite> SELECT * FROM user;
┌────┬────────────┬────────────┬─────┐
│ id │ first_name │ last_name │ age │
├────┼────────────┼────────────┼─────┤
│ 1 │ Steve │ Jobs │ 56 │
│ 2 │ Bill │ Gates │ 66 │
│ 3 │ Mark │ Zuckerberg │ 38 │
└────┴────────────┴────────────┴─────┘

And, this command below sets the output mode table:

.mode table

Then, you can set the output mode table as shown below:

sqlite> SELECT * FROM user;
+----+------------+------------+-----+
| id | first_name | last_name | age |
+----+------------+------------+-----+
| 1 | Steve | Jobs | 56 |
| 2 | Bill | Gates | 66 |
| 3 | Mark | Zuckerberg | 38 |
+----+------------+------------+-----+

And, these commands can show the details of the command .mode:

.help .mode

.help mode

.help modes

Then, you can show the details of the command .mode:

sqlite> .help .mode
.import FILE TABLE Import data from FILE into TABLE
 Options:
 --ascii Use 037円 and 036円 as column and row separators
 --csv Use , and \n as column and row separators
 --skip N Skip the first N rows of input
 --schema S Target table to be S.TABLE
 -v "Verbose" - increase auxiliary output
 Notes:
 * If TABLE does not exist, it is created. The first row of input
 determines the column names.
 * If neither --csv or --ascii are used, the input mode is derived
 from the ".mode" output mode
 * If FILE begins with "|" then it is a command that generates the
 input text.
.mode MODE ?OPTIONS? Set output mode
 MODE is one of:
 ascii Columns/rows delimited by 0x1F and 0x1E
 box Tables using unicode box-drawing characters
 csv Comma-separated values
 column Output in columns. (See .width)
 html HTML <table> code
 insert SQL insert statements for TABLE
 json Results in a JSON array
 line One value per line
 list Values delimited by "|"
 markdown Markdown table format
 qbox Shorthand for "box --width 60 --quote"
 quote Escape answers as for SQL
 table ASCII-art table
 tabs Tab-separated values
 tcl TCL list elements
 OPTIONS: (for columnar modes or insert mode):
 --wrap N Wrap output lines to no longer than N characters
 --wordwrap B Wrap or not at word boundaries per B (on/off)
 --ww Shorthand for "--wordwrap 1"
 --quote Quote output text as SQL literals
 --noquote Do not quote output text
 TABLE The name of SQL table used for "insert" mode

Lastly, you can show the commands .headers and .mode with .help as shown below:

sqlite> .help 
...
.headers on|off Turn display of headers on or off
...
.mode MODE ?OPTIONS? Set output mode
...

Answer 10

When you run the sqlite3 cli, typing in:

sqlite3 -header

will also give the desired result

• Ash: Weak answer. It's a CLI command. SQL query is expected.

Answer 11

.schema table_name

This will list down the column names of the table from the database.

Hope this will help!!!

Answer 12

This is an old question, but here is an alternative answer that retrieves all the columns in the SQLite database, with the name of the associated table for each column :

WITH tables AS (SELECT name tableName, sql 
FROM sqlite_master WHERE type = 'table' AND tableName NOT LIKE 'sqlite_%')
SELECT fields.name, fields.type, tableName
FROM tables CROSS JOIN pragma_table_info(tables.tableName) fields

This returns this type of result:

{
 "name": "id",
 "type": "integer",
 "tableName": "examples"
}, {
 "name": "content",
 "type": "text",
 "tableName": "examples"
}

For a simple table containing an identifier and a string content.

• Metro Smurf: Nice - this allows you to search all tables / fields. In my case, I needed to find all tables with some common field names.

Answer 13

you can use Like statement if you are searching for any particular column

ex:

SELECT * FROM sqlite_master where sql like('%LAST%')

Answer 14

In order to get the column information you can use the following snippet:

String sql = "select * from "+oTablename+" LIMIT 0";
Statement statement = connection.createStatement();
ResultSet rs = statement.executeQuery(sql);
ResultSetMetaData mrs = rs.getMetaData();
for(int i = 1; i <= mrs.getColumnCount(); i++)
{
 Object row[] = new Object[3];
 row[0] = mrs.getColumnLabel(i);
 row[1] = mrs.getColumnTypeName(i);
 row[2] = mrs.getPrecision(i);
}

• Erik Aronesty: this works with views, joins, etc. -- but what db wrapper is this?
• Devolus: It's simply jdbc. No wrapper.
• xeruf: jdbc is a wrapper ;)

Answer 15

//JUST little bit modified the answer of giuseppe which returns array of table columns
+(NSMutableArray*)tableInfo:(NSString *)table{
 sqlite3_stmt *sqlStatement;
 NSMutableArray *result = [NSMutableArray array];
 const char *sql = [[NSString stringWithFormat:@"PRAGMA table_info('%@')",table] UTF8String];
 if(sqlite3_prepare(md.database, sql, -1, &sqlStatement, NULL) != SQLITE_OK)
 {
 NSLog(@"Problem with prepare statement tableInfo %@",
 [NSString stringWithUTF8String:(const char *)sqlite3_errmsg(md.database)]);
 }
 while (sqlite3_step(sqlStatement)==SQLITE_ROW)
 {
 [result addObject:
 [NSString stringWithUTF8String:(char*)sqlite3_column_text(sqlStatement, 1)]];
 }
 return result;
}

Answer 16

.schema in sqlite console when you have you're inside the table it looks something like this for me ...

sqlite>.schema
CREATE TABLE players(
id integer primary key,
Name varchar(255),
Number INT,
Team varchar(255)

Answer 17

function getDetails(){
var data = [];
dBase.executeSql("PRAGMA table_info('table_name') ", [], function(rsp){
 if(rsp.rows.length > 0){
 for(var i=0; i<rsp.rows.length; i++){
 var o = {
 name: rsp.rows.item(i).name,
 type: rsp.rows.item(i).type
 } 
 data.push(o);
 }
 }
 alert(rsp.rows.item(0).name);
},function(error){
 alert(JSON.stringify(error));
}); 
}

• xeruf: Hey, I think the question was about the SQLite CLI. Please, add least add an explanation.

Answer 18

I know it's too late but this will help other.

To find the column name of the table, you should execute select * from tbl_name and you will get the result in sqlite3_stmt *. and check the column iterate over the total fetched column. Please refer following code for the same.

// sqlite3_stmt *statement ;
int totalColumn = sqlite3_column_count(statement);
for (int iterator = 0; iterator<totalColumn; iterator++) {
 NSLog(@"%s", sqlite3_column_name(statement, iterator));
}

This will print all the column names of the result set.

• xeruf: Hey, I think the question was about the SQLite CLI. You should mention which language you are using - is this plain C?

Answer 19

-(NSMutableDictionary*)tableInfo:(NSString *)table
{
 sqlite3_stmt *sqlStatement;
 NSMutableDictionary *result = [[NSMutableDictionary alloc] init];
 const char *sql = [[NSString stringWithFormat:@"pragma table_info('%s')",[table UTF8String]] UTF8String];
 if(sqlite3_prepare(db, sql, -1, &sqlStatement, NULL) != SQLITE_OK)
 {
 NSLog(@"Problem with prepare statement tableInfo %@",[NSString stringWithUTF8String:(const char *)sqlite3_errmsg(db)]);
 }
 while (sqlite3_step(sqlStatement)==SQLITE_ROW)
 {
 [result setObject:@"" forKey:[NSString stringWithUTF8String:(char*)sqlite3_column_text(sqlStatement, 1)]];
 }
 return result;
 }

Answer 20

I was able to retrieve table names with corresponding columns by using one sql query, but columns output is comma separated. I hope it helps somebody

SELECT tbl_name, (SELECT GROUP_CONCAT(name, ',') FROM PRAGMA_TABLE_INFO(tbl_name)) as columns FROM sqlite_schema WHERE type = 'table';

• Ed K: Perfect, this was exactly what I needed!

Answer 21

Get a list of tables and columns as a view:

CREATE VIEW Table_Columns AS
SELECT m.tbl_name AS TableView_Name, m.type AS TableView, cid+1 AS Column, p.*
FROM sqlite_master m, Pragma_Table_Info(m.tbl_name) p
WHERE m.type IN ('table', 'view') AND
 ( m.tbl_name = 'mypeople' OR m.tbl_name LIKE 'US_%') -- filter tables
ORDER BY m.tbl_name;

Answer 22

For use in Python with sqlite3

Top answer PRAGMA table_info() returns a list of tuples, which might not be suitable for further processing, e.g.:

[(0, 'id', 'INTEGER', 0, None, 0),
 (1, 'name', 'TEXT', 0, None, 0),
 (2, 'age', 'INTEGER', 0, None, 0),
 (3, 'profession', 'TEXT', 0, None, 0)]

When using sqlite3 in Python, simply add a list comprehension in the end to filter out unwanted information.

import sqlite3 as sq
def col_names(t_name):
 with sq.connect('file:{}.sqlite?mode=ro'.format(t_name),uri=True) as conn:
 cursor = conn.cursor()
 cursor.execute("PRAGMA table_info({}) ".format(t_name))
 data = cursor.fetchall()
 return [i[1] for i in data]
col_names("your_table_name")

Result

["id","name","age","profession"]

DISCLAIMER: Do not use in production as this snippet is subject to possible SQL injection!

Answer 23

I've not seen this elsewhere, but it seems to work for us: SELECT * FROM PRAGMA_table_list t JOIN PRAGMA_table_info(t.Name) c

• moo: What are the benefits of doing it this way instead of one of the shorter and more understandable suggestions in the other answers?

Answer 24

 //Called when application is started. It works on Droidscript, it is tested
 function OnStart()
 {
 //Create a layout with objects vertically centered. 
 lay = app.CreateLayout( "linear", "VCenter,FillXY" ); 
 //Create a text label and add it to layout.
 txt = app.CreateText( "", 0.9, 0.4, "multiline" ) 
 lay.AddChild( txt );
 app.AddLayout(lay);
 db = app.OpenDatabase( "MyData" ) 
 
 //Create a table (if it does not exist already). 
 db.ExecuteSql( "drop table if exists test_table" )
 db.ExecuteSql( "CREATE TABLE IF NOT EXISTS test_table " + 
 "(id integer primary key, data text, num integer)",[],null, OnError ) 
 db.ExecuteSql( "insert into test_table values (1,'data10',100), 
 (2,'data20',200),(3,'data30',300)")
 //Get all the table rows. 
 DisplayAllRows("SELECT * FROM test_table");
 DisplayAllRows("select *, id+100 as idplus, 'hahaha' as blabla from 
 test_table order by id desc;") 
 }
//function to display all records 
function DisplayAllRows(sqlstring) // <-- can you use for any table not need to 
 // know column names, just use a *
 // example: 
{ 
//Use all rows what is in ExecuteSql (try any, it will works fine)
db.ExecuteSql( sqlstring, [], OnResult, OnError ) 
} 
//Callback to show query results in debug. 
function OnResult( res ) 
{ 
var len = res.rows.length; 
var s = txt.GetText(); 
// ***********************************************************************
// This is the answer how to read column names from table:
for(var ColumnNames in res.rows.item(0)) s += " [ "+ ColumnNames +" ] "; // "[" & "]" optional, i use only in this demo 
// ***********************************************************************
//app.Alert("Here is all Column names what Select from your table:\n"+s);
s+="\n";
for(var i = 0; i < len; i++ ) 
{ 
 var rows = res.rows.item(i) 
 for (var item in rows) 
 {
 s += " " + rows[item] + " ";
 }
 s+="\n\n";
} 
//app.Alert(s);
txt.SetText( s ) 
} 
//Callback to show errors. 
function OnError( msg ) 
{ 
 app.Alert( "Error: " + msg ) 
} 

• TheQueenIsDead: This answer is too long and overly verbose, instead of posting code, please add more detail as to how and why this presents a solution for the user, such that it can be read and understood without having to be parsed first
• Attila Puskás: Hi, I just wanted share my idea, because i not fund complete resolved for my same problem before. There is the demo for the DroidScript. Enough a thanks or if you want I will delete my shared. Sorry my english.
• Community: As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center.

Answer 25

If you're using the SQLite3, INFORMATION_SCHEMA is not supported. Use PRAGMA table_info instead. This will return 6 rows of information about the table. To fetch the column name (row2), use a for loop like the following

cur.execute("PRAGMA table_info(table_name)") # fetches the 6 rows of data
records = cur.fetchall() 
print(records)
for row in records:
 print("Columns: ", row[1])

Answer 26

If you want to know the specific field is in the table or not you can use this code:

select * from pragma_table_info('yourTableName') as tblInfo
where name='yourFieldName'

Please fill yourTableNameand and yourFieldName.