Microsoft Access Query Tips and Techniques with SQL and VBA Code. Luke Chung, President of FMS, Inc. This paper is featured on: Overview. Microsoft Access is the most popular Windows database program. A primary reason for its success is its interactive query interface. Once data is collected in a database, analysis and updates need to be performed. Queries offer the ability to. Mastering Microsoft Access queries will improve your ability to manage and understand your data and simplify application development. Examples are for Microsoft Access 2. Also applies to Microsoft Access 2. Queries Hide the Complexity of Microsoft Access SQL Syntax. The visual representation of tables and the graphical links between them makes Microsoft Access queries extremely easy to use and hides the complexity of writing the raw Microsoft Access SQL. Fortunately, the nice user interface still allows. The entire query engine is modeled on SQL systems and can switch between the graphical query design and SQL syntax. Many Microsoft Access users and developers learned SQL from this feature. Knowing the many features of Microsoft Access queries allows you to perform advanced analysis quickly without programming. This presentation covers the basics of queries revealing a variety of subtleties. It quickly moves to more advanced. Finally, programmatic use of queries is presented: Download Sample Microsoft Access Query Database (1. K)Query Types. Microsoft Access supports many types of queries. ![]() Here is a description of the major categories: Select Queries. Retrieve records or summaries (totals) across records. Also includes cross- tabulations. Make Table Queries. Similar to Select queries but results are placed in a new table. Append Queries. Similar to Select queries but results are added to an existing table. Update Queries. Modify data in the records. Delete Queries. Records are deleted from a table. Select queries are the most common queries and can be used for viewing and a data source for forms, reports, controls, and other queries. The other queries create or change data and are known collectively as Action queries. Basic Select Queries. The most basic Select queries retrieve the records you specify from a table.
InformationWeek.com: News, analysis and research for business technology professionals, plus peer-to-peer knowledge sharing. Engage with our community. Microsoft made their new Azure App Service Tools extension available today in the Visual Studio Marketplace. I had the opportunity to preview this extension and was. You can choose the fields from a table to display. In the most cases, while viewing the query results you can modify. These updateable views are extremely powerful. Selecting Table and Fields The first step in creating a query is to specify the table or tables to use and the fields to display. Selecting tables is simple. Just choose the table from the list when the query is first created or use the Add Table command from the Query. The selected table is placed on the upper portion of the query design window. From there you can select the fields for the query. Shift- Click or Ctrl- Click) and dragging them to. QBE) grid. Make sure the Show option is checked to display the field. Sorting and Reordering Fields Once the fields are placed on the QBE grid, you can reorder the fields by clicking on the column and dragging it to the place you want. To sort the results, specify the Sort option under the fields to sort. You can choose Ascending or. Descending order. Note that you can turn off the Show setting and sort on a field that does not appear in the display. Renaming Fields A very nice feature of Microsoft Access queries is the ability to rename fields. You may have your data stored in field names that are. By using a query expression, you can change the field name the user sees. For instance, a field named "Cust. ID" could be changed to "Customer ID" by placing the new name followed by a colon and. QBE field cell: Customer ID: [Cust. ID]. Using Calculated Fields (Expressions) In addition to retrieving fields from a table, a Select query can also display calculations (expressions). Of course, expressions cannot be updated since they do not exist in the original table. Expressions are extremely powerful and allow you. There is an Expression Builder that simplifies the selection of fields and functions. By default. expression fields are named "Expr. Expr. 2", etc.; therefore, you usually want to rename them to something more understandable. Expression fields are also useful for sorting your records. Here's an example of using a calculated field to. Sort on Multiple Date (or Numeric) Fields with Blank Values in a Microsoft Access Query. Setting Query Properties While designing a query, you can choose View | Properties or right click on the top portion of the query and choose Properties to see and modify the query properties. Description. This property lets you provide a description for the query to help you remember its purpose. Default View. Show the results in a datasheet like a table, or a pivot chart or pivot table. Output All Fields. This option is usually set to No. If it is changed to Yes, all the fields of all the tables in the query are shown. In general, you should leave this property alone and specify the fields desired in the QBE grid. Top Values. Rather than retrieving all records, you can specify the top n records or n percent, where n is the value specified here. Unique Values. By default this is set to No and all records are retrieved. If this is changed to Yes, every record retrieved contains unique values. SQL uses the SELECT DISTINCT command). That is, no retrieved records are identical. For instance, you can run a query for the State field of the Patient table. With this set to No, the result is a record for each patient. When set to Yes, only the list of unique states is displayed. When set to Yes, the query is not updateable. Unique Records. By default this is set to No and all records are retrieved. For one table queries, this property is ignored. For multi- table queries, if it is set to Yes, (similar to using a DISTINCTROW in a SQL statement) only unique records in the underlying tables are retrieved. The Unique Records and Unique Values properties are linked and only one can be set to Yes (both can be No). When Unique Records is Yes, Unique Values is automatically set to No. When both properties are set to No, all records are returned. Difference between DISTINCT vs. DISTINCTROW These options sometimes appear to provide the same results, but there are significant differences. DISTINCT checks the results of query and eliminates duplicate rows. These queries (Unique Values = Yes) are not updateable. They are a snapshot of your data and don't reflect subsequent data modifications by users. This is similar to. Totals Query (e. g. Group By clause). DISTINCTROW checks all the fields in the table and then eliminates the duplicate rows. The results of a query with DISTINCTROW (Unique Records = Yes) are updateable and reflect changes to retrieved records (but the query does not. So the difference is that DISTINCT only checks the fields in the results, while DISTINCTROW checks all the fields in the underlying tables. If your query joins several tables and only displays records from one, the DISTINCTROW option lets you view and edit the results. For more information, visit Distinct versus Distinct. Row in Microsoft Access Queries. Non- Updateable Queries. Some queries are not updateable. For more information, read our paper addressing the warning message you see. This Recordset is not updateable: Dealing with non- updateable queries in Microsoft Access. SQL Server Properties. There are several properties related to SQL Server tables and are more technical and rarely need to be modified. For more information refer to Microsoft Access' on- line help system. Filter, Order By, Filter On Load, Order By On Load. Like a form, you can specify the Filter and Order By settings for a query. However, this is usually part of the query's SQL statement. By using the Filter and Order By properties, you have the extra advantage of specifying the Filter On Load and Order By On Load properties to apply them or not. Subdatasheet Name, Link Fields, and Size. If you want to display a subdatasheet to show a one- to- many relationship between the results in this query with data from another table. There is a significant performance cost for having subdatasheets, so only add them if you want them. Setting Field Properties. In addition to query properties, each field also has properties that can be set. Move to a field in the QBE grid and right click. Depending on the field type, different properties are available. The most important properties are for numeric and date fields. You can specify how the fields are formatted when the query is run. Viewing Results and SQL Equivalent.
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