Vb6 ado tutorial pdf

For example, if you include references to both ADO and DAO in the same project, you should include a qualifier to specify which object model to use when instantiating Recordset objects, as in the following code:. With the CreateObject method, the declaration and object instantiation must be two discrete steps:. Objects instantiated with CreateObject are late-bound, which means that they are not strongly typed and command-line completion is disabled.

However, it does allow you to skip referencing the ADO library from your project, and enables you to instantiate specific versions of objects. For example:. You could also accomplish this by specifically creating a reference to the ADO version 2. Instantiating objects by using the CreateObject method is typically slower than using the Dim statement.

The variable can be declared only as part of a class module and must be declared at the module level. Calling Web Services from Visual Basic 6. This article shows you how to build an application that downloads satellite photos of a given street address from Visual Basic 6.

This article, the first in a four-part series, shows that it is not necessary to migrate a Microsoft Visual Basic 6. NET in order to take advantage of. NET functionality. Enhancing a Visual Basic 6.

This article, the second in a four-part series, demonstrates how to use. This article, the third in a four-part series, shows how to include modern, simple-to-configure Microsoft Visual Basic.

This article shows how you can add automatic updating functionality to your existing Visual Basic 6. NET Framework 2. Deploying the Hybrid Visual Basic 6. NET Application. This article—the last in a four-part series that walks through enhancing an existing Microsoft Visual Basic 6. This article examines the functionality provided by the. Using Background Threads with Visual Basic 6. Learn how to use the. This article shows you how to inform the user of progress, how to allow the user to cancel the background task, and how to debug multi-threaded applications.

NET Framework - Part 1. NET Framework. NET Framework - Part 2. This article explains how you can use Visual Basic 6 with the. Accessing the Event Log from Visual Basic 6. Instrument your applications so that other people can look at the event logs to diagnose issues from Visual Basic 6. Access the File System with. Accessing the file system is a common application requirement, and in the spirit of Microsoft Visual Basic Fusion, this article shows how to access some of the best Microsoft.

Learn how to get the extension for a file, the directory portion or a path, or the file name portion of a path. Learn how to fire events every time the contents of a directory change.

While Microsoft no longer ships a migration wizard, our partners offer migration tools and solutions. Here are more resources to help answer questions on how to migrate from Visual Basic 6.

The first step in a phased migration to. NET is to assess which upgrade strategy is right for you in order to come up with a migration plan. See how to take advantage of. NET in your current VB6 applications. Gradual phased migration is made much easier with the Interop Forms Toolkit, but if a full upgrade is right for you, then check out or partner migration tools.

Leverage these tools and solutions from our partners to assist you with a more complete migration from Visual Basic 6 to. Microsoft Interop Forms Toolkit 2. Used to enable phased migration, this free add-in for Visual Studio simplifies the process of displaying. NET forms and controls in a Visual Basic 6 application. If a client side cursor location is selected then only optimistic and batch optimistic locking are available.

Returns the number of records in an open RecordSet. If for some reason ADO cannot determine the number of records then this will be set to Sets up an open record set to add a new record, once the required values have been set call the Update or UpdateBatch method to commit the changes.

Closes an open RecordSet object, make sure that any changes are committed using the Update or UpdateBatch method before closing or an error will be generated. Causes an open RecordSet object to move to the next record in the collection, if the current record is the last record then EOF is set to true. Opens the RecordSet, typically this is done with a valid Command object that includes the command text or SQL to get the records you want.

Causes any changes you have made in batch mode to be written to disk. I like to think of using ADO as a three step process Define and open a Connection to a data source Decide what data you need from the data source and define Command objects that will retrieve this data. Retrieve the data you require by executing the command objects and manipulate the data using RecordSet objects.

Then on the form add a single command button and add the code below to the click event of the button. Save the project and then open Microsoft Access and create a new database called "database. Add a table called "tabTestTable" to the database. Add two columns to this table with a text data type, the column names do not matter. Add a couple of records to the table with some values in the columns. If you dont want to do this I have created a VB project that includes all of this that can be downloaded.

Just unzip this to a directory and open the project in Visual Studio and try it out. Got questions? Feel free to ask me at questions timesheetsmts. Timesheets MTS Software Connection Object This object represents an open connection to the data source. Provider String A string defining the provider of a connection object. Mode connectModeEnum Sets or returns the permissions for modifying data across the open connection.

CursorLocation cursorLocationEnum Sets the location of the cursor engine. ConnectionTimeout Long Time in seconds that a connection will attempt to be opened before an error is generated. CommandTimeout Long Time in seconds that an command will attempt to be executed before an error is generated. Open Opens a connection with the settings in the ConnectionString property. Command Object A command object specifies a specific method you intend to execute on or against the data source accessed by an open connection.

Connection Defines the Connection object the command belongs to. CommandText String Contains the text of the command you want to execute against a data source. CommandType commandTypeEnum Defines the type of the command. RecordSet Object The RecordSet object represents a complete set of records from an executed command or from an underlying base table in the database.

Fields Collection Returns a collection of the field objects for an open record set. LockType LockTypeEnum sets the lock type on records when they are open for editing. Key Methods Name Description AddNew Sets up an open record set to add a new record, once the required values have been set call the Update or UpdateBatch method to commit the changes.

Close Closes an open RecordSet object, make sure that any changes are committed using the Update or UpdateBatch method before closing or an error will be generated. MoveNext Causes an open RecordSet object to move to the next record in the collection, if the current record is the last record then EOF is set to true.

MoveFirst Causes an open RecordSet object to move to the first record in the collection. MoveLast Causes an open RecordSet object to move to the last record in the collection.