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

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?

24 Answers

PRAGMA table_info(table_name);

will get you a list of all the column names.

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

If you do

.headers ON

you will get the desired result.

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 } }

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

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 (2017-01-02).

Reference:

To get a list of columns you can simply use:

.schema tablename

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;

When you run the sqlite3 cli, typing in:

sqlite3 -header

will also give the desired result

.schema table_name

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

Hope this will help!!!

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

ex:

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

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); }

//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; }

.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)

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)); }); }

-(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; }

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.

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.

This command below sets column names:

.header on