테이블의 열 수를 구합니다

테이블의 열 수를 구합니다

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테이블에서 행 수를 찾을 수 있습니다.

select count(*) from tablename

테이블에서 열 수를 찾을 수 있습니까?

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SELECT COUNT(*)
  FROM INFORMATION_SCHEMA.COLUMNS
 WHERE table_catalog = 'database_name' -- the database
   AND table_name = 'table_name'

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SELECT COUNT(COLUMN_NAME) 
FROM INFORMATION_SCHEMA.COLUMNS 
WHERE 
    TABLE_CATALOG = 'Database name' 
    AND TABLE_SCHEMA = 'dbo' 
    AND TABLE_NAME = 'table name'

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SELECT count(*)
FROM information_schema.columns
WHERE table_name = 'Your_table_nale';

참고 : Your_table_nale은 테이블 이름으로 바꿉니다.

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Java에서 JDBC 사용 :

    String quer="SELECT * FROM sample2";

    Statement st=con.createStatement();
    ResultSet rs=st.executeQuery(quer);
    ResultSetMetaData rsmd = rs.getMetaData();
    int NumOfCol=0;
    NumOfCol=rsmd.getColumnCount();
    System.out.println("Query Executed!! No of Colm="+NumOfCol);

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또는 sys.columns를 사용하십시오.

--SQL 2005
SELECT  *
FROM    sys.columns
WHERE   OBJECT_NAME(object_id) = 'spt_values'
-- returns 6 rows = 6 columns

--SQL 2000
SELECT  *
FROM    syscolumns
WHERE   OBJECT_NAME(id) = 'spt_values'
-- returns 6 rows = 6 columns

SELECT  *
FROM    dbo.spt_values
    -- 6 columns indeed

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조금 늦었지만 제발 가져 가세요 ...

편집기 (새 쿼리) 에서 데이터베이스 객체 를 선택하면 테이블도 될 수 있습니다. 단축 키 Alt + F1 을 사용하면 객체의 모든 정보를 얻을 수 있으며 문제도 해결할 것이라고 생각합니다.

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SELECT COUNT(COLUMN_NAME) FROM INFORMATION_SCHEMA.COLUMNS WHERE 
TABLE_CATALOG = 'database_name' AND TABLE_SCHEMA = 'dbo'
AND TABLE_NAME = 'table_name'

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SELECT count(*) FROM information_schema.`COLUMNS` C
WHERE table_name = 'your_table_name'
AND TABLE_SCHEMA = "your_db_name"

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글쎄, Nathan Koop의 대답을 시도했지만 그것은 효과가 없었습니다. 나는 그것을 다음과 같이 바꾸었고 효과가 있었다.

SELECT COUNT(*)
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'table_name'

내가 넣어 경우에도 작동하지 않았다 USE 'database_name'아니다 WHERE table_catalog = 'database_name' AND table_name' = 'table_name'. 나는 실제로 이유를 알게되어 기쁠 것입니다.

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It is possible to find the number of columns in a table just by using 3 simple lines of PHP code.

$sql="SELECT * FROM table";
$query=mysqli_query($connect_dude,$sql);    
$num=mysqli_num_fields($query);

$num would return the number of columns on a given table in this case.

Hopefully,it would help others.

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Query to count the number of columns in a table:

select count(*) from user_tab_columns where table_name = 'tablename';

Replace tablename with the name of the table whose total number of columns you want returned.

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Can get using following sql statement:

select count(*) Noofcolumns from SYSCOLUMNS where id=(select id from SYSOBJECTS where name='table_name')

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Following query finds how columns in table:-

 SELECT COUNT(COLUMN_NAME) FROM USER_TAB_COLUMNS
 WHERE TABLE_NAME = 'TableName';

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A MySQL answer adapted slightly from the MSDN example for MySqlDataReader.GetValues:

//assumes you've already created a connection, opened it, 
//and executed a query to a reader

while(reader.Read())
{
    Object[] values = new Object[reader.FieldCount];
    int fieldCount = reader.GetValues(values);

    Console.WriteLine("\nreader.GetValues retrieved {0} columns.",   fieldCount);
    for (int i = 0; i < fieldCount; i++)
        Console.WriteLine(values[i]);
}

Using MySqlDataReader.FieldCount will allow you to retrieve the number of columns in the row you've queried.

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SELECT COUNT(*) 
FROM INFORMATION_SCHEMA.COLUMNS 
WHERE 
   TABLE_NAME = 'table_name';

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SELECT TABLE_SCHEMA
    , TABLE_NAME
    , number = COUNT(*) 
FROM INFORMATION_SCHEMA.COLUMNS
GROUP BY TABLE_SCHEMA, TABLE_NAME;

This one worked for me.

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Since all answers are using COUNT(), you can also use MAX() to get the number of columns in a specific table as

SELECT MAX(ORDINAL_POSITION) NumberOfColumnsInTable
FROM INFORMATION_SCHEMA.COLUMNS
WHERE TABLE_CATALOG = 'YourDatabaseNameHere'
      AND 
      TABLE_SCHEMA = 'YourSchemaNameHere'
      AND
      TABLE_NAME = 'YourTableNameHere';

See The INFORMATION_SCHEMA COLUMNS Table

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db2 'describe select * from "SCHEMA_NAME"."TBL_NAME"'

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Here is how you can get a number of table columns using Python 3, sqlite3 and pragma statement:

con = sqlite3.connect(":memory:")    
con.execute("CREATE TABLE tablename (d1 VARCHAR, d2 VARCHAR)")
cur = con.cursor()
cur.execute("PRAGMA table_info(tablename)")
print(len(cur.fetchall()))

Source

참고URL : https://stackoverflow.com/questions/658395/find-the-number-of-columns-in-a-table