EAV Query selection from tables with extended values

Question

I have the following SQL Server database structure that I should use to query data. The model may be wrong; I appreciate the arguments, if so, so I can ask for changes. If not, I need a query to retrieve tabbed data in a format that I will discuss in detail below.

The structure is as follows:

CLIENTS:

ClientID    ClientName
-----------------------
1           James
2           Leonard
3           Montgomery

ATTRIBUTES:

AttributeID     AttributeName
-----------------------------
1               Rank
2               Date
3               Salary
4               FileRecordsAmount

ATTRIBUTES_STRING:

ClientID    AttributeID     AttributeStringValue
1           1               Captain
2           1               Chief Surgeon
3           1               Chief Engineer

ATTRIBUTES_NUMERIC:

ClientID    AttributeID     AttributeNumericValue
1           4               187
2           4               2
3           4               10

As a result, I will need the following:

RESULTS:
----------------------------------------------------------
ClientID    ClientName  Rank            FileRecordsAmount
1           James       Captain         187
2           Leonard     Chief Surgeon   2
3           Montgomery  Chief Engineer  10

How can i achieve this?

Many thanks!

EDIT: The difficult problem here (for me) is that the attributes are dynamic ... I have 5 attribute tables (ATTRIBUTES_STRING, ATTRIBUTES_NUMERIC, ATTRIBUTES_DATE, ATTRIBUTES_BIT, ATTRIBUTES_INT), and the user should be able to configure its attributes.

Answer 1

SQL. :

select 
    CLIENTS.ClientID, 
    CLIENTS.ClientName, 
    ATTRIBUTES_STRING1.AttributeStringValue as Rank, 
    ATTRIBUTES_NUMERIC2.AttributeNumericValue as FileRecordsAmount
from 
    CLIENTS,
    ATTRIBUTES ATTRIBUTES1,
    ATTRIBUTES ATTRIBUTES2,
    ATTRIBUTES_STRING ATTRIBUTES_STRING1,
    ATTRIBUTES_NUMERIC ATTRIBUTES_NUMERIC2
where CLIENTS.ClientID = ATTRIBUTES_STRING1.ClientID
and CLIENTS.ClientID = ATTRIBUTES_NUMERIC2.ClientID
and ATTRIBUTES_STRING1.AttributeID = ATTRIBUTES1.AttributeID
and ATTRIBUTES_NUMERIC2.AttributeID = ATTRIBUTES2.AttributeID
and ATTRIBUTES1.AttributeName = 'Rank'
and ATTRIBUTES2.AttributeName = 'FileRecordsAmount'
;

SQL Fiddle . EAV, :)

: , :

create table CLIENTS (
    ClientID integer primary key,
    ClientName varchar(50) not null
);

insert into CLIENTS values (1,'James');
insert into CLIENTS values (2,'Leonard');
insert into CLIENTS values (3,'Montgomery');

create table ATTRIBUTES (
    AttributeID integer primary key,
    AttributeName varchar(50) not null
);

create index ATTRIBUTE_NAME_IDX on ATTRIBUTES (AttributeName);

insert into ATTRIBUTES values (1,'Rank');
insert into ATTRIBUTES values (2,'Date');
insert into ATTRIBUTES values (3,'Salary');
insert into ATTRIBUTES values (4,'FileRecordsAmount');

create table ATTRIBUTES_STRING (
    ClientID integer,
    AttributeID integer not null,
    AttributeStringValue varchar(255) not null,
    primary key (ClientID, AttributeID)
);

insert into ATTRIBUTES_STRING values (1,1,'Captain');
insert into ATTRIBUTES_STRING values (2,1,'Chief Surgeon');
insert into ATTRIBUTES_STRING values (3,1,'Chief Engineer');

create table ATTRIBUTES_NUMERIC (
    ClientID integer,
    AttributeID integer not null,
    AttributeNumericValue numeric(10, 5) not null,
    primary key (ClientID, AttributeID)
);
insert into ATTRIBUTES_NUMERIC values (1,4,187);
insert into ATTRIBUTES_NUMERIC values (2,4,2);
insert into ATTRIBUTES_NUMERIC values (3,4,10);

: ,