In the design view of the table, each field has a design type, Access allows nine data types: text, note, value, date / time, currency, automatic number, yes / no, OLE object, hyperlink, query wizard.
Text: This type allows up to 255 characters or numbers. The ACCESS default size is 50 characters, and the system only saves characters in the field without saving the empty characters in the unused location in the text field. You can set the "Field Size" property to control the maximum character length of the entered. Remarks: This type is used to save longer text and numbers that allow fields to store content with up to 64,000 characters. But Access cannot sort or index the note field, but you can sort and index the text field. Although you can search for text in the Remarks field, it is better to search for fast as you have an indexed text field. Number: This type of field type can be used to store digital data for arithmetic computing, and the user can set "Field Size" attribute to define a specific number type, and any font specified as a digital data type can be set to "byte", "Integer", "Long Integer", "Single Joint Number", "Double Accuracy", "Synchronous Replication ID", "Decan" five types. It usually defaults to "double precision" in Access. Date / Time: This type is used to store dates, time, or date time, each date / time field requires 8 bytes to store space. Currency: This type is a special type of digital data type, equivalent to a digital field type with a double precision attribute. When entering data to the currency field, you don't have to type the comma in the RMB symbol and thousands. Access will automatically display the renminbi symbols and commas and add two decimal to currency fields. When the decimal part is more than two digits, Access will go all over the data. Accuracy is a decimal point 15 digits and the 4 digits of the right square. Automatic number: This type is more special. When adding new records to the table, Access will automatically insert a unique order or random number, which specifies a certain value in the Auto Number field. Once the auto number is specified, it will be permanently connected to the record. If you delete a record containing the Auto Number field, Access does not re-numbered the table automatic number field. When a certain record is added, Access no longer uses the value of the automatic number field that has been deleted, but re-assapts the incremental rules. YES / NO: This field is a field set up to only two different optional values in a field. By the format feature of the / no data type, the user can choose to select / no fields. OLE object: This field means that the field allows "link" or "embedded" OLE object separately. When adding data to the OLE object field, you can link or embed an OLE object in an Access table refers to an object created by other OLE protocol programs, such as Word documents, Excel spreadsheets, images, sounds, or other binary data. The OLE object field is up to 1GB, which is mainly limited by disk space. Hyper link: This field is primarily used to save the hyperlink, including the text as a hyperlink address or a combination of characters and numbers stored in text form. When you click a hyperlink, the web browser or Access will reach the specified target based on the hyperlink address. The super link can contain three parts: First, the text displayed in the field or control; the other is the path to the file or page; the third is the address in the file or page. The easiest way to insert a hyperlink address in this field or control is to click the "Hyper Link" command in the Insert menu. Check the Wizard: This field type provides the user with a list of field content, which can be selected as the content of the listed field as the content of the field in the list.
Supplement 2: Establish an index in the table
In a relatively small database, retrieval data is relatively fast. However, when the data in the database table is getting more and more, the work directly searching data is very heavy, the speed is very slow, this time you need to establish a claim to help Access more effectively search data. To establish an index in a table, first open a table with a design view, use a mouse to select a field, then move the mouse to the properties box of this field, and then click the Index Properties box, the right side of the box appears down arrows. Click it and select the appropriate option in the pop-up box, "None" indicates that this field establishes an index, "There is (no repetition)" indicates that the field has an index, but this index cannot be repeated, and "there is (no repetition) "Also indicates that this field establishes an index, but it is possible to repeat. These are the process of establishing a single field index. If you often provide multiple criteria when you search for large-scale, you need to create several field indexes. To create a multi-defined index in the table, you will move the mouse to the "Index" button on the toolbar, click this button, pop up "Index" dialog, in the table above, the leftmost is the index name to be established, used to enter the name of the index, the middle is the field name, indicating the field name of the corresponding field of the index, the rightmost It is a sort order, here the sorting method of each record in the field. Add 3: How to use uppercase letters to display English text fields
Use the designer to open a table with the mouse list, then move the mouse to the attribute of the field, click the text box on the right of the "Format" property, when a flashing "|" symbol appears in the text box, enter " > "Symbol, switch back to the data sheet format, then discover all the letters in the field of the original single-write mix to become uppercase. If you enter the "<" symbol in the Format box, all letters of this field will be arranged in lowercase.
