如果一列有多个键，如何从DB获得结果？

Question

Well, I've a table called keywords and there are 2 columns.

1) kid
2) keywords (keyword value)

and I've another table called contact_details where there a column called keyword . In this keyword column I'm inserting many keyword from keywords table. So 2 tables is look like this...

Keywords table:

kid    keyword
1      php     
1      mysql     
1      html     
1      css     
1      css3     
1      wp     
1      photoshop     
1      3d

contact_details table:

cid    name    phone   keyword
1      alex    123     php, mysql, hmtl
2      alex1   124     php, html, css3
3      alex2   125     wp, html, css
4      alex3   126     photoshop, 3d
5      alex4   127     html, 3d, php
6      alex5   128     mysql, wp, html

Now I've a search box which is searching people (name From contact_details table) by using keyword value. In search box, Search value could be few keywords. I mean it's could be php, mysql, html or could be php, 3d, photoshop .

So My question is : how can I write a Sql query to get the result ? I want to get all name which match the search keyword/s from contact_details table ?

Is there any field need to add in keywords table ? Can not get an IDEA :(

Answer 1

Select name from contact_details where keyword like '%<search keywords>%'

Like search keyword key php then you need pass php in query and will get list of all name which having keywords as php'

Select name from contact_details where keyword like '%php%'

hope this will resolve your issue.

Proper approach, Make kid as primary key in Keyword table

Keywords table:
kid    keyword
1      php     
2      mysql     
3      html 

Remove keywords column from contact_details table.

contact_details table:
cid    name    phone   
1      alex    123     
2      alex1   124     
3      alex2   125 

Make one more table which having many to many relationship and you need insert the relationship here so that no need touch again keywords and contact_details table again.

keyword_contact_mapping
kcid   kid_fk   cid_fk
1      1        1     
2      1        2
3      1        3
4      2        1    
5      2        1 
6      2        2
7      2        3

Sql query (Not tested you can also use alias)

select name from contact_details join keyword_contact_mapping on kid_fk =(select kid from Keywords where keyword='php')

Answer 2

Assuming you have the ID when the name is selected, you can use:

    SELECT Keyword from Keywords_Table
    WHERE ID = <ID>

Answer 3

USE AdventureWorksDW2008R2
GO

IF OBJECT_ID('Keywords') IS NOT NULL
BEGIN
    DROP TABLE Keywords
END

IF OBJECT_ID('Contact_Details') IS NOT NULL
BEGIN
    DROP TABLE Contact_Details
END


IF OBJECT_ID('Keyword_ContactDetails') IS NOT NULL
BEGIN
    DROP TABLE Keyword_ContactDetails
END

/* automate id's with identity. Or, do you want to specify the the keyword id manually? 
*/
CREATE TABLE Keywords(
    Keywords_ID INT IDENTITY(1,1) NOT NULL
    ,Keyword NVARCHAR(100)

    CONSTRAINT PK_Keywords PRIMARY KEY
    (
        Keywords_ID
    )   
)
  /* You must plan each column data type by careful consideration
     I am using the phone example here to demonstrate different business requirements
     the lenghts and datatype may need to change for localization
  */
CREATE TABLE Contact_Details
(
     Contact_Details_ID INT IDENTITY(1,1) NOT NULL
    ,First_Name VARCHAR(100)
    ,Last_Name  VARCHAR(100)
    ,Phone      VARCHAR(10)
    ,Phone_EXT  VARCHAR(3)
    ,Phone_International NVARCHAR(15)

    CONSTRAINT PK_Contact_Details PRIMARY KEY
    (
        Contact_Details_ID
    )
)

CREATE TABLE Keyword_ContactDetails
(
     Keyword_ID INT
    ,Contact_Details_ID INT
    ,DateTime_Created DATETIME

    CONSTRAINT PK_KeywordContact PRIMARY KEY
    (
        Keyword_ID
        ,Contact_Details_ID
    )

    /*Enforce referential integrity, 
      prevents adding keywords that don't exist
      prevents deleting a keyword if it is referenced   
    */
    FOREIGN KEY (Keyword_ID) REFERENCES Keywords(Keywords_ID),
    FOREIGN KEY (Contact_Details_ID) REFERENCES Contact_Details(Contact_Details_ID)

)

/* Populate keywords
*/

INSERT INTO Keywords(Keyword) VALUES ('PHP')
INSERT INTO Keywords(Keyword) VALUES ('MYSQL')
INSERT INTO Keywords(Keyword) VALUES ('HTML')
INSERT INTO Keywords(Keyword) VALUES ('CSS')

/* Add contact details
*/
INSERT INTO Contact_Details(
                First_Name
                ,Last_Name
                ,Phone
                ,Phone_EXT
                ,Phone_International)
            VALUES(
                'Abe'
                ,'Lincoln'
                ,'2129996677'
                ,'123'
                ,'na')


/* Assign PHP Keyword to Abe Lincoln
*/
DECLARE @keywordID int = 0
        ,@contactDetails int = 0

set @keywordID = (select Keywords_ID from Keywords where Keyword = 'PHP')
set @contactDetails = (select Contact_Details_ID from Contact_Details where Last_Name = 'Lincoln')

INSERT INTO Keyword_ContactDetails(
            Keyword_ID
            ,Contact_Details_ID
            ,DateTime_Created)
            VALUES(
            @keywordID
            ,@contactDetails
            ,CURRENT_TIMESTAMP)



SELECT * FROM Contact_Details C
JOIN Keyword_ContactDetails KC
ON KC.Contact_Details_ID = C.Contact_Details_ID
JOIN    Keywords K
ON K.Keywords_ID = KC.Keyword_ID