Java OracleCallableStatement Arayüzü

cosntructor
Şöyle yaparız.

oracle.jdbc.OracleConnection connection = ...;
OracleCallableStatement callableStatement = (OracleCallableStatement) connection
  .prepareCall("{call bss_acc.ACC_STATEMENT(?,?,?,?)}");

TO_DATE Metodu

Giriş
İmzası şöyle. String parametre Date'e çevrilir. TO_CHAR metodu Date'i string'e çevirir.

TO_DATE( date_string, format_model, nls_params )

Açıklaması şöyle.

TO_DATE function just converts string to date

Örnek
Şöyle yaparız.

TO_DATE ('10-AUG-2016')

Örnek
Elimizde '20190801' olsun. Sadece ay kısmını almak için şöyle yaparız.

select extract(month from to_date(ID_BB_SECURITY, 'YYYYMMDD')) from BT_EXPORT

MM - Ay Numarası

Örnek
Şöyle yaparız.

select employee_id from employee
 where employee_date_hired > to_date('31-12-1995','DD-MM-YYYY')

Ay numarası yerine ay ismi verilmez. Şu kod yanlış.

select * from   emp_tasks
where  TASK_START_DATE > to_Date('30-MAR-18','DD-MM-YYYY');

Örnek
Şöyle yaparız.

TO_DATE(PHOTO_ACCEPTENCE_DATE,'DD-MM-YY')

MON - Ay İsmi
Ay isimleri NLS_DATE_LANGUAGE ve NLS_DATE_FORMAT ayarlarına bağlı. Çok güvenmemek lazım.
Örnek
Şöyle yaparız.

select employee_id from employee
 where employee_date_hired > to_date('31-DEC-95','DD-MON-YY')

ALTER TABLE

Giriş
ALTER TABLE veya DROP COLUMN sadece metadata ile ilgilidir. Açıklaması şöyle.

There are certain circumstances where dropping a column can be a meta-data-only operation. The column definitions for any given table are not included in each and every page where rows are stored, column definitions are only stored in the database metadata, including sys.sysrowsets, sys.sysrscols, etc.

When dropping a column that is not referenced by any other object, the storage engine simply marks the column definition as no longer present by deleting the pertinent details from various system tables. When a query subsequently references that table, it skips the bytes stored in each page for that column, as if the column no longer exists.

When a subsequent DML operation occurs against the table, the pages that are affected are re-written without the data for the dropped column. If you rebuild a clustered index or a heap, all the bytes for the dropped column are naturally not written back to the page on disk. This effectively spreads the load of dropping the column over time, making it less noticeable.

Örnek
Sütuna "default değer" ve "NOT NULL" vermek için şöyle yaparız.

ALTER TABLE table_name
  MODIFY (column_1 varchar2(100) DEFAULT 'some default' NOT NULL,
          column_2 varchar2(75) DEFAULT 'Some Value' NOT NULL);

BLOB

Örnek
Açıklaması şöyle.

Notice that the binary literal format on Oracle is different than MySQL. This is another reason that you should avoid using binary literals in SQL statements to make your Java program portable.

Şöyle yaparız.

Statement sta = con.createStatement();

// Inserting CLOB value with a regular insert statement
int count = sta.executeUpdate(
        "INSERT INTO Image"
        +" (ID, Subject, Body)"
        +" VALUES (1, '"+subject+"'"
        +", 'C9CBBBCCCEB9C8CABCCCCEB9C9CBBB')"); //Oracle format
//      +", 0xC9CBBBCCCEB9C8CABCCCCEB9C9CBBB)"); //SQL Server format
//      +", x'C9CBBBCCCEB9C8CABCCCCEB9C9CBBB')"); // MySQL format

TO_CHAR Metodu

Örnek
Şöyle yaparız.

Select TO_CHAR(sysdate,'dd-mm-yyyyy') from dual;

CREATE TRIGGER

Örnek
Şöyle yaparız.

CREATE TABLE x (i NUMBER(10));

CREATE TRIGGER x_int_trg
 BEFORE INSERT OR UPDATE ON x
 REFERENCING NEW AS new
 FOR EACH ROW
  BEGIN
   IF :new.i NOT BETWEEN -2147483648 AND 2147483647 THEN
    raise_application_error(-20000, 'Not a 32 bit integer');
  END IF;
END x_int_trg;
/

Örnek
Şöyle yaparız.

CREATE OR REPLACE TRIGGER SYS.LOGON_TRIGGER
  AFTER LOGON ON DATABASE
DECLARE
  THIS_USER VARCHAR2(50);
BEGIN
  SELECT OSUSER INTO THIS_USER FROM V$SESSION WHERE SID = SYS_CONTEXT('USERENV','SID');
  IF THIS_USER NOT IN (<List of Users>)
    THEN RAISE LOGIN_DENIED;
  ENDIF;
END;
/