Oracle PL/SQL Tutorial/Table/Merge

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Содержание

MERGE INTO

SQL>
SQL>
SQL> -- create demo table
SQL> CREATE TABLE Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL PRIMARY KEY,
  3    First_Name         VARCHAR2(10 BYTE),
  4    Last_Name          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /
TABLE created.
SQL>
SQL> -- prepare data
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2               VALUES ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York",  "Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York",  "Manager")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
  3  /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> SELECT * FROM Employee
  2  /
ID   FIRST_NAME           LAST_NAME            START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- -------------------- -------------------- --------- --------- ---------- ---------- ---------------
01   Jason                Martin               25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer
02   Alison               Mathews              21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester
03   James                Smith                12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia                Rice                 24-OCT-82 21-APR-99    2344.78 Vancouver  Manager
05   Robert               Black                15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda                Green                30-JUL-87 04-JAN-96    4322.78 New York   Tester
07   David                Larry                31-DEC-90 12-FEB-98    7897.78 New York   Manager
08   James                Cat                  17-SEP-96 15-APR-02    1232.78 Vancouver  Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL> CREATE TABLE new_employee AS SELECT * FROM employee;
CREATE TABLE new_employee AS SELECT * FROM employee
 
SQL>
SQL> UPDATE new_employee SET salary = salary +1;
8 rows updated.
SQL>
SQL> UPDATE new_employee SET id = id +1;
8 rows updated.
SQL>
SQL> SELECT * FROM new_employee;
ID   FIRST_NAME           LAST_NAME            START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- -------------------- -------------------- --------- --------- ---------- ---------- ---------------
3    Jason                Martin               25-JUL-96 25-JUL-06    1236.56 Toronto    Programmer
4    Alison               Mathews              21-MAR-76 21-FEB-86    6663.78 Vancouver  Tester
5    James                Smith                12-DEC-78 15-MAR-90    6546.78 Vancouver  Tester
6    Celia                Rice                 24-OCT-82 21-APR-99    2346.78 Vancouver  Manager
7    Robert               Black                15-JAN-84 08-AUG-98    2336.78 Vancouver  Tester
8    Linda                Green                30-JUL-87 04-JAN-96    4324.78 New York   Tester
9    David                Larry                31-DEC-90 12-FEB-98    7899.78 New York   Manager
10   James                Cat                  17-SEP-96 15-APR-02    1234.78 Vancouver  Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL> MERGE INTO employee e
  2  USING new_employee ne ON (
  3    e.id = ne.id
  4  )
  5  WHEN NOT MATCHED THEN
  6    INSERT (e.id, e.first_name, e.last_name, e.description, e.salary)
  7    VALUES (ne.id,ne.first_name,ne.last_name,ne.description,ne.salary);
8 rows merged.
SQL>
SQL> SELECT * FROM employee;
ID   FIRST_NAME           LAST_NAME            START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- -------------------- -------------------- --------- --------- ---------- ---------- ---------------
01   Jason                Martin               25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer
02   Alison               Mathews              21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester
03   James                Smith                12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia                Rice                 24-OCT-82 21-APR-99    2344.78 Vancouver  Manager
05   Robert               Black                15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda                Green                30-JUL-87 04-JAN-96    4322.78 New York   Tester
07   David                Larry                31-DEC-90 12-FEB-98    7897.78 New York   Manager
08   James                Cat                  17-SEP-96 15-APR-02    1232.78 Vancouver  Tester
3    Jason                Martin                                      1236.56            Programmer
4    Alison               Mathews                                     6663.78            Tester
5    James                Smith                                       6546.78            Tester
6    Celia                Rice                                        2346.78            Manager
7    Robert               Black                                       2336.78            Tester
8    Linda                Green                                       4324.78            Tester
9    David                Larry                                       7899.78            Manager
10   James                Cat                                         1234.78            Tester
16 rows selected.
SQL>
SQL> DROP TABLE new_employee;
TABLE dropped.
SQL>
SQL>
SQL> -- clean the table
SQL> DROP TABLE Employee
  2  /
TABLE dropped.
SQL>


Merge table

SQL>
SQL> CREATE TABLE myTable
  2  (pid number, sales number, STATUS varchar2(6));
TABLE created.
SQL>
SQL> CREATE TABLE myTable2
  2  (pid number, sales number, STATUS varchar2(6));
TABLE created.
SQL>
SQL> INSERT INTO myTable2 VALUES(1,12,"CURR");
1 row created.
SQL> INSERT INTO myTable2 VALUES(2,13,"NEW" );
1 row created.
SQL> INSERT INTO myTable2 VALUES(3,15,"CURR");
1 row created.
SQL>
SQL> INSERT INTO myTable  VALUES(2,24,"CURR");
1 row created.
SQL> INSERT INTO myTable  VALUES(3, 0,"OBS" );
1 row created.
SQL> INSERT INTO myTable  VALUES(4,42,"CURR");
1 row created.
SQL>
SQL> SELECT * FROM myTable2;
       PID      SALES STATUS
---------- ---------- ------
         1         12 CURR
         2         13 NEW
         3         15 CURR
SQL> SELECT * FROM myTable;
       PID      SALES STATUS
---------- ---------- ------
         2         24 CURR
         3          0 OBS
         4         42 CURR
SQL>
SQL> merge INTO myTable2 m
  2        USING myTable d
  3        ON (m.pid = d.pid)
  4  when  matched
  5  then  UPDATE SET   m.sales  = m.sales+d.sales
  6               ,     m.STATUS = d.STATUS
  7        DELETE WHERE m.STATUS = "OBS"
  8  when  NOT matched
  9  then  INSERT VALUES (d.pid,d.sales,"NEW");
3 rows merged.
SQL>
SQL> SELECT * FROM myTable2;
       PID      SALES STATUS
---------- ---------- ------
         1         12 CURR
         2         37 CURR
         4         42 NEW
SQL>
SQL>
SQL> DROP TABLE myTable;
TABLE dropped.
SQL> DROP TABLE myTable2;
TABLE dropped.
SQL>


Merge table into another table

SQL> CREATE TABLE student_emails_ext
  2   (firstname    varchar(40),
  3    lastname     varchar(40),
  4    email        varchar(80) );
TABLE created.
SQL>
SQL> CREATE TABLE student_emails
  2  AS SELECT * FROM student_emails_ext
  3     WHERE 0=1
  4  /
TABLE created.
SQL>
SQL>
SQL> merge INTO student_emails s
  2  USING (SELECT * FROM student_emails_ext) e
  3  ON (s.firstname = e.firstname AND s.lastname = e.lastname)
  4  when matched then
  5       UPDATE SET s.email = e.email
  6  when NOT matched then
  7       INSERT (s.firstname, s.lastname, s.email)
  8       VALUES(e.firstname , e.lastname, e.email);
0 rows merged.
SQL>
SQL> DROP TABLE student_emails_ext;
TABLE dropped.
SQL> DROP TABLE student_emails;
TABLE dropped.


Merge two tables and map columns

SQL>
SQL> -- create demo table
SQL> CREATE TABLE emp(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    fname         VARCHAR2(10 BYTE),
  4    lname          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /
TABLE created.
SQL>
SQL> -- prepare data
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2               VALUES ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York",  "Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York",  "Manager")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
  3  /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> SELECT * FROM emp
  2  /
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
01   Jason      Martin     25-JUL-96 25-JUL-06    1234.56 Toronto
Programmer
02   Alison     Mathews    21-MAR-76 21-FEB-86    6661.78 Vancouver
Tester
03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
04   Celia      Rice       24-OCT-82 21-APR-99    2344.78 Vancouver
Manager
05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver
Tester
06   Linda      Green      30-JUL-87 04-JAN-96    4322.78 New York
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York
Manager
08   James      Cat        17-SEP-96 15-APR-02    1232.78 Vancouver
Tester
 
8 rows selected.
SQL>
SQL>
SQL> CREATE TABLE new_emp AS SELECT * FROM emp;
TABLE created.
SQL>
SQL> UPDATE new_emp SET salary = salary +1;
8 rows updated.
SQL> UPDATE new_emp SET id = id +1;
8 rows updated.
SQL>
SQL> SELECT * FROM new_emp;
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
2    Jason      Martin     25-JUL-96 25-JUL-06    1235.56 Toronto
Programmer
3    Alison     Mathews    21-MAR-76 21-FEB-86    6662.78 Vancouver
Tester
4    James      Smith      12-DEC-78 15-MAR-90    6545.78 Vancouver
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
5    Celia      Rice       24-OCT-82 21-APR-99    2345.78 Vancouver
Manager
6    Robert     Black      15-JAN-84 08-AUG-98    2335.78 Vancouver
Tester
7    Linda      Green      30-JUL-87 04-JAN-96    4323.78 New York
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
8    David      Larry      31-DEC-90 12-FEB-98    7898.78 New York
Manager
9    James      Cat        17-SEP-96 15-APR-02    1233.78 Vancouver
Tester
 
8 rows selected.
SQL>
SQL> --Merging Rows Using MERGE
SQL> --merge rows from one table into another
SQL>
SQL> MERGE INTO emp e
  2  USING new_emp ne ON (e.id = ne.id)
  3  WHEN NOT MATCHED THEN
  4  INSERT (e.id, e.fname, e.lname, e.description, e.salary)VALUES(ne.id,ne.fna
me,ne.lname,ne.description,ne.salary);
8 rows merged.
SQL>
SQL> -- clean the table
SQL> DROP TABLE new_emp;
TABLE dropped.
SQL> DROP TABLE emp
  2  /
TABLE dropped.
SQL>
SQL>


Merge two tables when matched or not matched

SQL>
SQL>
SQL> CREATE TABLE myTable(pid number, sales number, STATUS varchar2(6));
TABLE created.
SQL> CREATE TABLE master_tab(pid number, sales number, STATUS varchar2(6));
TABLE created.
SQL>
SQL> INSERT INTO master_tab VALUES(1,12,"CURR");
1 row created.
SQL> INSERT INTO master_tab VALUES(2,13,"NEW" );
1 row created.
SQL> INSERT INTO master_tab VALUES(3,15,"CURR");
1 row created.
SQL>
SQL> INSERT INTO myTable  VALUES(2,24,"CURR");
1 row created.
SQL> INSERT INTO myTable  VALUES(3, 0,"OBS" );
1 row created.
SQL> INSERT INTO myTable  VALUES(4,42,"CURR");
1 row created.
SQL>
SQL>
SQL> merge INTO master_tab m
  2        USING myTable d
  3        ON (m.pid = d.pid)
  4  when  matched
  5  then  UPDATE SET   m.sales  = m.sales+d.sales
  6               ,     m.STATUS = d.STATUS
  7        DELETE WHERE m.STATUS = "OBS"
  8  when  NOT matched
  9  then  INSERT VALUES (d.pid,d.sales,"NEW");
3 rows merged.
SQL>
SQL> SELECT * FROM master_tab;
       PID      SALES STATUS
---------- ---------- ------
         1         12 CURR
         2         37
         4         42 NEW
SQL>
SQL>
SQL>
SQL> DROP TABLE myTable;
TABLE dropped.
SQL> DROP TABLE master_tab;
TABLE dropped.
SQL>


Merge two tables with update

SQL>
SQL> -- create demo table
SQL> CREATE TABLE emp(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  3    fname         VARCHAR2(10 BYTE),
  4    lname          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /
TABLE created.
SQL>
SQL> -- prepare data
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2               VALUES ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York",  "Tester")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York",  "Manager")
  3  /
1 row created.
SQL> INSERT INTO emp(ID,  fname, lname, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
  3  /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> SELECT * FROM emp
  2  /
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
01   Jason      Martin     25-JUL-96 25-JUL-06    1234.56 Toronto
Programmer
02   Alison     Mathews    21-MAR-76 21-FEB-86    6661.78 Vancouver
Tester
03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
04   Celia      Rice       24-OCT-82 21-APR-99    2344.78 Vancouver
Manager
05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver
Tester
06   Linda      Green      30-JUL-87 04-JAN-96    4322.78 New York
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York
Manager
08   James      Cat        17-SEP-96 15-APR-02    1232.78 Vancouver
Tester
 
8 rows selected.
SQL>
SQL>
SQL> CREATE TABLE new_emp AS SELECT * FROM emp;
TABLE created.
SQL>
SQL> UPDATE new_emp SET salary = salary +1;
8 rows updated.
SQL>
SQL> SELECT * FROM new_emp;
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
01   Jason      Martin     25-JUL-96 25-JUL-06    1235.56 Toronto
Programmer
02   Alison     Mathews    21-MAR-76 21-FEB-86    6662.78 Vancouver
Tester
03   James      Smith      12-DEC-78 15-MAR-90    6545.78 Vancouver
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
04   Celia      Rice       24-OCT-82 21-APR-99    2345.78 Vancouver
Manager
05   Robert     Black      15-JAN-84 08-AUG-98    2335.78 Vancouver
Tester
06   Linda      Green      30-JUL-87 04-JAN-96    4323.78 New York
Tester
 
ID   FNAME      LNAME      START_DAT END_DATE      SALARY CITY
---- ---------- ---------- --------- --------- ---------- ----------
DESCRIPTION
---------------
07   David      Larry      31-DEC-90 12-FEB-98    7898.78 New York
Manager
08   James      Cat        17-SEP-96 15-APR-02    1233.78 Vancouver
Tester
 
8 rows selected.
SQL>
SQL> --Merging Rows Using MERGE
SQL> --merge rows from one table into another
SQL>
SQL> MERGE INTO emp e
  2  USING new_emp ne ON (e.id = ne.id)
  3  WHEN MATCHED THEN UPDATE SET e.salary = ne.salary;
8 rows merged.
SQL>
SQL>
SQL> -- clean the table
SQL> DROP TABLE new_emp;
TABLE dropped.
SQL> DROP TABLE emp
  2  /
TABLE dropped.
SQL>


Merge with match

SQL>
SQL> -- create demo table
SQL> CREATE TABLE Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL PRIMARY KEY,
  3    First_Name         VARCHAR2(10 BYTE),
  4    Last_Name          VARCHAR2(10 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(10 BYTE),
  9    Description        VARCHAR2(15 BYTE)
 10  )
 11  /
TABLE created.
SQL>
SQL> -- prepare data
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2               VALUES ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)
  2                VALUES("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York",  "Tester")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York",  "Manager")
  3  /
1 row created.
SQL> INSERT INTO Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)
  2                VALUES("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
  3  /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> SELECT * FROM Employee
  2  /
ID   FIRST_NAME           LAST_NAME            START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- -------------------- -------------------- --------- --------- ---------- ---------- ---------------
01   Jason                Martin               25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer
02   Alison               Mathews              21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester
03   James                Smith                12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia                Rice                 24-OCT-82 21-APR-99    2344.78 Vancouver  Manager
05   Robert               Black                15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda                Green                30-JUL-87 04-JAN-96    4322.78 New York   Tester
07   David                Larry                31-DEC-90 12-FEB-98    7897.78 New York   Manager
08   James                Cat                  17-SEP-96 15-APR-02    1232.78 Vancouver  Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL> CREATE TABLE new_employee AS SELECT * FROM employee;
TABLE created.
SQL>
SQL> UPDATE new_employee SET salary = salary +1;
8 rows updated.
SQL>
SQL> UPDATE new_employee SET id = id +1;
8 rows updated.
SQL>
SQL> SELECT * FROM new_employee;
ID   FIRST_NAME           LAST_NAME            START_DAT END_DATE      SALARY CITY       DESCRIPTION
---- -------------------- -------------------- --------- --------- ---------- ---------- ---------------
2    Jason                Martin               25-JUL-96 25-JUL-06    1235.56 Toronto    Programmer
3    Alison               Mathews              21-MAR-76 21-FEB-86    6662.78 Vancouver  Tester
4    James                Smith                12-DEC-78 15-MAR-90    6545.78 Vancouver  Tester
5    Celia                Rice                 24-OCT-82 21-APR-99    2345.78 Vancouver  Manager
6    Robert               Black                15-JAN-84 08-AUG-98    2335.78 Vancouver  Tester
7    Linda                Green                30-JUL-87 04-JAN-96    4323.78 New York   Tester
8    David                Larry                31-DEC-90 12-FEB-98    7898.78 New York   Manager
9    James                Cat                  17-SEP-96 15-APR-02    1233.78 Vancouver  Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL> --Merging Rows Using MERGE
SQL> --merge rows from one table into another
SQL>
SQL> MERGE INTO employee e
  2  USING new_employee ne ON (
  3    e.id = ne.id
  4  )
  5  WHEN MATCHED THEN
  6    UPDATE
  7    SET
  8       e.salary = ne.salary;
0 rows merged.
SQL>
SQL>
SQL> -- clean the table
SQL> DROP TABLE Employee
  2  /
TABLE dropped.
SQL>