• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Queries
 

 

Statistics

Views

Total Views
809
Views on SlideShare
728
Embed Views
81

Actions

Likes
0
Downloads
8
Comments
0

1 Embed 81

http://rriness.spscc.edu 81

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Queries Queries Presentation Transcript

    • Queries
      CIS-145
    • Select Queries
      Method to find, organize, summarize data & create information
      Uses data from tables, other queries
      Can include calculations
    • Design View
      Identify where to get data
      Specify which rows to use
      Identify fields, calculations to return
      How to order the results
    • Datasheet View
      “Dynaset” is the result of a query
      “Dynamic subset”
      Saving a query saves the “question” not the answer
    • Select Query Design View
      Run Button
      Table
      Criteria
    • Select Query Dynaset
      The results of the query
      are displayed as a dynaset
    • Creating a Query
      Identify where the data is coming from
      Determine which rows are part of your answer
      Identify any groups or summaries needed
      Specify which groups are part of the answer
      Select the fields or calculations to include in the result
      Apply sorting to help users understand result
    • Query Data Sources
      Queries can use tables or queries as data sources
      If more than one table is needed for the query result a join is required
      Make sure that there is a connection (join) to each table
      Make sure you can find common values to connect each table
    • Joins
      Connect tables temporarily when query executes
      Access will create a join automatically where tables have a relationship
      Join fields should be on fields that are the same data type
    • Types of Joins
      Inner Join
      Default join
      Looking for matching values in both tables
      If a table has a value not found in the second table nothing is returned
      Outer Join
      Allows query to return rows that don’t have a match in the other table
      Cartesian Join
      Combines all rows whether match or not
    • Query Criteria
      Which rows should be included?
      Criteria are True/False conditions/comparisons
      Conditions can use:
      Relational operators (=, >, <, <=, >=, <>)
      Between
      Like (patterns, Wild cards)
    • Wild Cards
      Wild cards can help describe patters
      ? – one character in a particular space
      * - zero, one, or morecharacters
      S?ND returns SAND, SEND
      S*ND returns SAND, SENT, STAND, SOUND
    • Logical Operators
      Needed when there are multiple criteria
      AND condition: all tests must be passed
      OR condition: as long as one test is passed the row is included
      NOT creates the inverse
      If something returns True, NOT makes it False
    • Grouping
      Grouping (“totals queries” in Access) provides summaries about data
      Can create summary values using Aggregate functions
      How many? (Count)
      How much? (Sum)
      Can summarize all rows or find common values to create groups
      Total Credits v. Total Credits for each department
    • Sorting
      Query results can be sorted
      Access works from left to right when sorting if multiple fields are sorted