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Posts Tagged ‘query

SubSonic Tutorial ( Learn basics )

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Following code uses version 2.2 and Northwind database as an example to illustrate the basics. You can use Linq queries also which is introduced from 2.1 pakala release. The same tutorial is in the following two files in case it is hard to read the following tutorial.

Insert the Record

 

//Fill the object to save. Please make sure that you fill all must (not null) object

Supplier sup = new Supplier();

sup.Address = "Test Address";

sup.City = "Ahmedabad";

sup.CompanyName = "IntelliPro";

sup.ContactName = "Test Contact";

sup.ContactTitle = "Manager";

sup.Country = "India";

sup.Fax = "01234567";

sup.HomePage = "http://www.xyz.com";

sup.Phone = "01293202";

sup.PostalCode = "380051";

sup.Region = "Test Region";

 

// call save

sup.Save();

 

Update the Record

 

//Fetch the object which is required to save. 30 is id of record

Supplier sup = new Supplier(30);

 

// Fill the property which needs to be saved.

sup.PostalCode = "380052";

sup.Region = "TestRegion2";

 

// call save

sup.Save();

 

Delete the Record

 

//If there are IsDelete flag then this function make true in this column. Else it delete the record from the database.

Supplier.Delete(30);

 

//In case you have IsDelete flag and you want to delete the function, use following code.

Supplier.Destroy(30);

 


 

Select all Record

 

// You can select all the record 2 ways.

// First using supplier object

SupplierCollection colSup = new SupplierCollection();

colSup.LoadAndCloseReader(Supplier.FetchAll());

 

// now colSup has all the record

 

// Second is just us collection’s Load method

SupplierCollection colSup = new SupplierCollection();

colSup.Load();

 

Select record by primary key

 

// 30 is primary key and in new object just pass it to the constructor

Supplier sup = new Supplier(30);

 

// if object successfully fetched from the database then following property will be true. So you can check to verify the record sometime whether record is loaded or not.

sup.IsLoaded

Select record by parameter other than primary key (but only one parameter)

 

 

SupplierCollection colSup = new SupplierCollection();

// It defaults to equal operation in FetchByParameter function

colSup.LoadAndCloseReader(Supplier.FetchByParameter (Supplier.Columns.Country,"India") );

 

// IF you want to use another comparision operator, you can use

colSup.LoadAndCloseReader(Supplier.FetchByParameter (Supplier.Columns.Country, SubSonic.Comparison.NotEquals,"India") );

 

 

// You can also apply order by at the end. To generate order by, you must use its static function Asc or Desc

// e.g. OrderBy.Asc or OrderBy.Desc and supply column name into the same.

colSup.LoadAndCloseReader(Supplier.FetchByParameter (Supplier.Columns.Country, SubSonic.Comparison.NotEquals,"India", OrderBy.Asc(Supplier.Columns.City) ) );

Following are the list of comparisions which we can use into comparing the parameter.

public enum Comparison

    {

        Equals = 0,

        NotEquals = 1,

        Like = 2,

        NotLike = 3,

        GreaterThan = 4,

        GreaterOrEquals = 5,

        LessThan = 6,

        LessOrEquals = 7,

        Blank = 8,

        Is = 9,

        IsNot = 10,

        In = 11,

        NotIn = 12,

        OpenParentheses = 13,

        CloseParentheses = 14,

        BetweenAnd = 15,

    }

Select record by parameter other than primary key (but more than one parameter)

 

// There are two methods for doing this. You can use any.

 

// First one is following

SupplierCollection colSup = new SupplierCollection();

 

colSup.Where(Supplier.Columns.City,"Ahmedabad");

colSup.Where(Supplier.Columns.CompanyName, Comparison.Like ,"Intelli");

 

// you can also use order by before calling Load function to order the result.

colSup.OrderByAsc(Supplier.Columns.PostalCode);

 

// Following statement load the records with above condition. Here one thing to note that

// It only uses where and that also with AND default. you cannot do OR here. For that

// you need to use second option

colSup.Load();

 

// Here is second method for doing the similar kind of thing

 

// Here you need to pass tablename or schema in the query.

// If Tables structure is available then you can pass Tables.Supplier else you can pass

// TableName.schema object

Query qry = new Query(Supplier.Schema);

 

// Query has many function and you can use multiple function for your query

qry.AddWhere(Supplier.Columns.City,"Ahmedabad");

qry.OR(Supplier.Columns.CompanyName, Comparison.Like ,"Intelli");

 

qry.OrderBy = OrderBy.Asc(Supplier.Columns.City);

 

SupplierCollection colSup = new SupplierCollection();

// It defaults to equal operation in FetchByParameter function

colSup.LoadAndCloseReader(qry.ExecuteReader());

 

 


 

Other Methods of the Query Objects

 

// Set order by. Its property. You can use order_by function as well.

qry.OrderBy

 

// Make In and Non In query

qry.IN

qry.NOT_IN

 

// And and OR condition

qry.AND

qry.OR

 

// Where condition

qry.AddWhere

 

// Find record between values

qry.AddBetweenValues

 

// Find record between dates

qry.AddBetweenAnd

 

You have other methods of query to execute other than execute reader.

You can use, Execute for update query, ExecuteDataSet for getting dataset and ExecuteScaler for scalar values.

Select from more than one table 

There is no method available in 2.0.3 for the join. So we will use only View right now. But there are other method in latest version of subsonic for directly making  Joins.

Suppose you wanted Invoices from the 5 tables joined, you can create the view Invoice and then you can use that object same way like tables and also you can query view to filter the data like tables.

Calling Stored Procedures

When you generate classes, the class is generated automatically for each stored procedure and views. For stored procedure SPs class is generated and all stored procedures are as static function so you can directly call without creating object as I have done below. You can find stored procedure in Northwind database.

StoredProcedure spSales =  SPs.SalesByCategory("Test","2009");

DataSet ds =  spSales.GetDataSet();

 

// Generally we use object’s collection to take the result in. So we can create one view like

// SalesByCategoryResult and take this result into it by calling funcitons like that

 

SalesByCategoryResultCollection colSup = new SalesByCategoryResultCollection();

colSup.LoadAndCloseReader(spSales.GetReader());

 

Customized Query (Which do not fit in any of above point)

 

There are two ways. Either you can make stored procedure and generate the SP function and use it or you can make the query as below.

// Make sql statement. But make sure that you do not hardcode any values. Below query can be made with subsonic

// but it is used just only for example.

string query = "SELECT * FROM " + Supplier.Schema.TableName + " WHERE " + Supplier.Columns.Address + " LIKE %abc%";

 

// Now create querycommand object with above query

QueryCommand qc = new QueryCommand(query);

 

// DataService class is used to run query command object. QueryCommand object is generally used for

// making parameterized queries which might not be fitted using query object. And you can take those

// Values in Collection

SupplierCollection colSup = new SupplierCollection();

colSup.LoadAndCloseReader(DataService.GetReader(qc));

Aggregate Functions

If you want to use aggregate function on some table, you can use it following way.

Query qry = new Query(Supplier.Schema);

 

// following returns Maximum supplierid in the table

int SupplierId = qry.GetMax(Supplier.Columns.SupplierID);

 

//There are other functions available for aggregate in query

qry.GetAverage

qry.GetCount

qry.GetMin

qry.GetSum

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Written by Manish

November 7, 2009 at 10:46 pm

Posted in .NET, Time Saver

Tagged with , , ,

How to query different type database object like table, view, trigger using sysobject

with one comment

 

following is the query for selecting all object from all database

SELECT      name, id, xtype, uid, info, status, base_schema_ver,  replinfo, parent_obj, crdate, ftcatid, schema_ver,  stats_schema_ver, type, userstat, sysstat, indexdel,  refdate,version, deltrig, instrig, updtrig, seltrig,  category, cache
FROM        sys.sysobjects

There are various parameter which you can use as where to specify criteria.

If you want to search certain object type then

XTYPE =

‘U’ For table
‘PK’ For Primary Keys
‘F’ For Foreight Keys
‘V’ For views
‘P’ For stored procedures
‘TR’ For triggers
‘S’ For system objects
‘FN’ Function

 

You can also add like query on name to give specific resultset.

Written by Manish

August 25, 2009 at 4:22 pm

Posted in .NET

Tagged with , ,