Oracle PL/SQL/Char Functions/LENGTH — различия между версиями

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Текущая версия на 09:58, 26 мая 2010

Combine length and translate

 
SQL>
SQL> select length(
  2             translate("how many consonants are there?",
  3                       "bcdfghjklmnpqrstvwxzaeiouy? ",
  4                       "bcdfghjklmnpqrstvwxz")
  5           ) "# of consonants"
  6  from dual
  7  /
# of consonants
---------------
             15
1 row selected.
SQL>
SQL> --



LENGTH: return the length of a string value, a numeric value

SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
  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> --LENGTH: return the length of a string value, a numeric value.
SQL>
SQL> SELECT First_name, LENGTH(First_name) AS LENGTH FROM Employee;
FIRST_NAME     LENGTH
---------- ----------
Jason               5
Alison              6
James               5
Celia               5
Robert              6
Linda               5
David               5
James               5
8 rows selected.
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.
SQL>
SQL>
SQL>



length with null value

 
SQL>
SQL>
SQL> CREATE TABLE EMP
  2  (EMPNO NUMBER(4) NOT NULL,
  3   ENAME VARCHAR2(10),
  4   JOB VARCHAR2(9),
  5   MGR NUMBER(4),
  6   HIREDATE DATE,
  7   SAL NUMBER(7, 2),
  8   COMM NUMBER(7, 2),
  9   DEPTNO NUMBER(2)
 10  );
Table created.
SQL>
SQL> INSERT INTO EMP VALUES (7369, "SMITH",  "CLERK",     7902,TO_DATE("17-DEC-1980", "DD-MON-YYYY"),  800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7499, "ALLEN",  "SALESMAN",  7698,TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600,  300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7521, "WARD",   "SALESMAN",  7698,TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250,  500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7566, "JONES",  "MANAGER",   7839,TO_DATE("2-APR-1981", "DD-MON-YYYY"),  2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN",  7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7698, "BLAKE",  "MANAGER",   7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"),  2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7782, "CLARK",  "MANAGER",   7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"),  2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7788, "SCOTT",  "ANALYST",   7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7839, "KING",   "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN",  7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"),  1500,    0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7876, "ADAMS",  "CLERK",     7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7900, "JAMES",  "CLERK",     7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"),   950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7902, null,   "ANALYST",   7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"),  3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK",     7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10);
1 row created.
SQL>
SQL> select ename, length( ename ) from emp;
ENAME      LENGTH(ENAME)
---------- -------------
SMITH                  5
ALLEN                  5
WARD                   4
JONES                  5
MARTIN                 6
BLAKE                  5
CLARK                  5
SCOTT                  5
KING                   4
TURNER                 6
ADAMS                  5
JAMES                  5
MILLER                 6
14 rows selected.
SQL>
SQL> drop table emp;
Table dropped.
SQL>
SQL>
SQL> --



use Length function in where statement

 
SQL>
SQL>
SQL>
SQL> CREATE TABLE product (
  2       product_name     VARCHAR2(25),
  3       product_price    NUMBER(4,2),
  4       quantity_on_hand NUMBER(5,0),
  5       last_stock_date  DATE);
Table created.
SQL>
SQL> INSERT INTO product VALUES ("Small Widget", 99, 1, "15-JAN-03");
1 row created.
SQL> INSERT INTO product VALUES ("Medium Widget", 75, 1000, "15-JAN-02");
1 row created.
SQL> INSERT INTO product VALUES ("Product Number", 50, 100, "15-JAN-03");
1 row created.
SQL> INSERT INTO product VALUES ("Round Church Station", 25, 10000, null);
1 row created.
SQL>
SQL>
SQL>
SQL> SELECT   product_name, LENGTH(product_name) NAME_LENGTH
  2  FROM     product
  3  WHERE    LENGTH(product_name) >15
  4  ORDER BY product_name;
PRODUCT_NAME              NAME_LENGTH
------------------------- -----------
Round Church Station               20
SQL>
SQL>
SQL>
SQL> DROP TABLE product;
Table dropped.