в 13:45, 26 мая 2010

2010-05-26T13:45:46Z

Admin: 1 версия

2010-05-26T10:11:39Z

1 версия

Новая страница

== LENGTH(x) get the number of characters in x==

The following example displays the length of the strings in the first_name column.



<source lang="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> SELECT first_name, LENGTH(first_name) FROM employee;
FIRST_NAME LENGTH(FIRST_NAME)
---------- ------------------
Jason 5
Alison 6
James 5
Celia 5
Robert 6
Linda 5
David 5
James 5
8 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL></source>

== Order by the length of employee name==



<source lang="sql">
SQL>
SQL>
SQL> create table employees(
2 empno NUMBER(4)
3 , ename VARCHAR2(8)
4 , init VARCHAR2(5)
5 , job VARCHAR2(8)
6 , mgr NUMBER(4)
7 , bdate DATE
8 , msal NUMBER(6,2)
9 , comm NUMBER(6,2)
10 , deptno NUMBER(2) ) ;
Table created.
SQL>
SQL>
SQL> insert into employees values(1,"Jason", "N", "TRAINER", 2, date "1965-12-18", 800 , NULL, 10);
1 row created.
SQL> insert into employees values(2,"Jerry", "J", "SALESREP",3, date "1966-11-19", 1600, 300, 10);
1 row created.
SQL> insert into employees values(3,"Jord", "T" , "SALESREP",4, date "1967-10-21", 1700, 500, 20);
1 row created.
SQL> insert into employees values(4,"Mary", "J", "MANAGER", 5, date "1968-09-22", 1800, NULL, 20);
1 row created.
SQL> insert into employees values(5,"Joe", "P", "SALESREP",6, date "1969-08-23", 1900, 1400, 30);
1 row created.
SQL> insert into employees values(6,"Black", "R", "MANAGER", 7, date "1970-07-24", 2000, NULL, 30);
1 row created.
SQL> insert into employees values(7,"Red", "A", "MANAGER", 8, date "1971-06-25", 2100, NULL, 40);
1 row created.
SQL> insert into employees values(8,"White", "S", "TRAINER", 9, date "1972-05-26", 2200, NULL, 40);
1 row created.
SQL> insert into employees values(9,"Yellow", "C", "DIRECTOR",10, date "1973-04-27", 2300, NULL, 20);
1 row created.
SQL> insert into employees values(10,"Pink", "J", "SALESREP",null,date "1974-03-28", 2400, 0, 30);
1 row created.
SQL>
SQL> select lower(job), initcap(ename)
2 from employees
3 where upper(job) = "SALESREP"
4 order by length(ename);
LOWER(JO INITCAP(
-------- --------
salesrep Joe
salesrep Pink
salesrep Jord
salesrep Jerry
SQL>
SQL>
SQL> drop table employees;
Table dropped.</source>

== Use length() function three times in a select statement==



<source lang="sql">
SQL>
SQL> CREATE TABLE book(
2 title_id CHAR(3) NOT NULL,
3 title_name VARCHAR(40) NOT NULL,
4 type VARCHAR(10) NULL ,
5 pub_id CHAR(3) NOT NULL,
6 pages INTEGER NULL ,
7 price DECIMAL(5,2) NULL ,
8 sales INTEGER NULL ,
9 pubdate DATE NULL ,
10 contract SMALLINT NOT NULL
11 );
Table created.
SQL>
SQL>
SQL>
SQL> INSERT INTO book VALUES("T01","Java","history","P01",111,21.99,566,DATE "2000-08-01",1);
1 row created.
SQL> INSERT INTO book VALUES("T02","Oracle","history","P03", 114,19.95,9566,DATE "1998-04-01",1);
1 row created.
SQL> INSERT INTO book VALUES("T03","SQL","computer","P02", 122,39.95,25667,DATE "2000-09-01",1);
1 row created.
SQL> INSERT INTO book VALUES("T04","C++","psychology","P04", 511,12.99,13001,DATE "1999-05-31",1);
1 row created.
SQL> INSERT INTO book VALUES("T05","Python","psychology","P04", 101,6.95,201440,DATE "2001-01-01",1);
1 row created.
SQL> INSERT INTO book VALUES("T06","JavaScript","biography","P01", 173,19.95,11320,DATE "2000-07-31",1);
1 row created.
SQL> INSERT INTO book VALUES("T07","LINQ","biography","P03", 331,23.95,1500200,DATE "1999-10-01",1);
1 row created.
SQL> INSERT INTO book VALUES("T08","C#","children","P04", 861,10.00,4095,DATE "2001-06-01",1);
1 row created.
SQL> INSERT INTO book VALUES("T09","SQL Server","children","P04", 212,13.95,5000,DATE "2002-05-31",1);
1 row created.
SQL> INSERT INTO book VALUES("T10","AJAX","biography","P01", NULL,NULL,NULL,NULL,0);
1 row created.
SQL> INSERT INTO book VALUES("T11","VB","psychology","P04", 821,7.99,94123,DATE "2000-11-30",1);
1 row created.
SQL> INSERT INTO book VALUES("T12","Office","biography","P01", 507,12.99,100001,DATE "2000-08-31",1);
1 row created.
SQL> INSERT INTO book VALUES("T13","VBA","history","P03", 812,29.99,10467,DATE "1999-05-31",1);
1 row created.
SQL>
SQL>
SQL> SELECT title_name,
2 LENGTH(title_name) AS "Len"
3 FROM book
4 WHERE LENGTH(title_name) < 30
5 ORDER BY LENGTH(title_name) ASC;
TITLE_NAME Len
---------------------------------------- ----------
VB 2
C# 2
VBA 3
SQL 3
C++ 3
Java 4
LINQ 4
AJAX 4
Office 6
Oracle 6
Python 6
TITLE_NAME Len
---------------------------------------- ----------
SQL Server 10
JavaScript 10
13 rows selected.
SQL>
SQL> drop table book;
Table dropped.
SQL>
SQL>
SQL></source>

== Use Length() to deal with number column==

The following example displays the total number of characters that make up the salary using LENGTH().
The decimal point (.) is counted in the number of salary characters.



<source lang="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> SELECT salary, LENGTH(salary) FROM employee;
SALARY LENGTH(SALARY)
---------- --------------
1234.56 7
6661.78 7
6544.78 7
2344.78 7
2334.78 7
4322.78 7
7897.78 7
1232.78 7
8 rows selected.
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL></source>

← Предыдущая	Версия 13:45, 26 мая 2010
(нет различий)

Oracle PL/SQL Tutorial/Character String Functions/LENGTH - История изменений

в 13:45, 26 мая 2010

Admin: 1 версия