How can worksheet be connected with database explain

The behavior of this option is affected by whether you select Enforced or Trusted. Trusted: Enables the use of dimension and constraint information that has been declared trustworthy by the database administrator but that has not been validated by the database. If the dimension and constraint information is valid, performance may improve. However, if this information is invalid, then the refresh procedure may corrupt the materialized view even though it returns a success status.

If you want to make any changes, go back to the relevant panes and make the changes there. Displays the results of the DDL commands. If there are any errors, go to the appropriate pane, fix the errors, and run the commands again. You can save to a text file or clear the output. The Index Properties dialog box is displayed when you create or edit an index. You can create and edit in three ways:. Right-click a table in the worksheet Navigator tab, and select Add Index. To edit, right-click an index in the Navigator tab and select Edit.

Expression : A column name or column expression. A column expression is an expression built from columns, constants, SQL functions, and user-defined functions. Selected Columns : Columns selected for the index. Order : ASC for an ascending index index values sorted in ascending order ; DESC for a descending index index values sorted in descending order.

If you want to make any changes, go back to the Definition pane and make the changes there. When you are finished, click Apply. If there are any errors, go to the Definition pane, fix the errors, and run the commands again. This Sequence Properties Dialog is displayed when you right-click a sequence object in the worksheet Navigator tab and select Add Sequence or Edit Sequence.

These options are also available when you right-click a table object in the Data Modeler Navigator tab. A sequence is an object from which multiple users may generate unique integers.

If you want to make any changes, go back to the Properties pane and make the changes there. If there are any errors, go to the Properties pane, fix the errors, and run the commands again. You have save to a text file or clear the output. The View Properties Dialog is displayed when you create or edit a view.

To create or edit, right-click a view in the worksheet Navigator tab, and select New or Edit. A semicolon is not required after the query. Click the Refresh Columns icon to automatically populate the columns in this pane.

You can edit the columns by selecting the required row and making changes in the Header Alias and Comments fields.

Force on Create : Select Yes to create the view regardless of whether the base tables of the view or the referenced object types exist or the owner of the schema containing the view has privileges on them.

FORCE fails if the base table does not exist or the referenced object type does not exist. FORCE also fails if the view definition names a constraint that does not exist. Query Restriction : Read Only prevents the view from being used to add, delete, or change data in the underlying table.

Check Option prohibits any changes to the underlying table that would produce rows that are not included in this view. Based on the inputs provided, the DDL statements are generated. You can review and save the SQL statements. If you want to make any changes, go back to the relevant pane and make the changes there. If there are any errors, go to the respective pane, fix the errors, and run the commands again. Query Result : Displays the results of the most recent Run Statement operation in a display table.

Explain Plan : Displays the plan for your query using the Explain Plan command. Displays the output if you clicked the Autotrace icon. To re-enter a previously executed query in the worksheet, double-click the query in the history list. You can search for specific statements by clicking the Search icon. The Search functionality is case-sensitive, retrieves all entries that contain the search text, and does not require wildcard characters.

Show info : Displays the SQL statement for which the output is displayed. Open in new tab : Opens the query result or explain plan in a new window. Download : This is applicable only for Query Result.

In the Query Result tab, in the display table, the context menu right-click for the row header consists of the following:. Sort displays a dialog box for selecting columns to sort by. For each column, you can specify ascending or descending order, and you can specify that null values be displayed first.

Count Rows displays the number of rows in the result set for your query. Single Record View enables you to view data for a table or view, one record at a time. Previous Next JavaScript must be enabled to correctly display this content. Database administrators can also access the worksheet from the Quick Links pane in Dashboard. For context-related help, click the icon. You can drag objects from the Navigator and drop them into the worksheet editor in the right pane: If you drag and drop a table or view, you are prompted to select one of the following SQL statements: Insert, Update, Select, or Delete.

The various object types and the corresponding options are: Tables : Tables are used to hold data. Note: The worksheets are saved in the browser. F1 Opens the help topic. F5 Runs code as script. F6 Shows Autotrace. F10 Shows Explain Plan. Note: Editing a partitioned table is not recommended. For a partitioned table, when you right-click and select Edit , a warning message is displayed.

This is how you can identify whether the table is partitioned or not. Columns pane Specifies properties for each column in the table. General tab Lists the columns currently in the table. Name : Name for the column. Datatype : Data type for the column. Expression : Expression for computing the value in the column. In the table: PK : If this option is selected, the column becomes the primary key. Check Constraint: Name : Name for the check constraint definition.

Identity Column tab Applicable for Oracle Database 12c and later releases. Start with : Starting value of the sequence.

Increment : Interval between successive numbers in a sequence. Primary Key pane Specifies the primary key for the table. An index is automatically created on the primary key. Index : Name of the index to which the primary key refers. Tablespace : Name of the tablespace associated with the index. Unique Keys pane Specifies one or more unique constraints for the table. Name : Name of the unique constraint.

Index : Name of the index to which the unique key refers. Indexes pane Lists the indexes currently defined on the table. Name : Name of the index. Tablespace : Name of the tablespace for the index. Foreign Keys pane Specifies one or more foreign keys for the table.

Name : Name of the foreign key definition. Enabled : If this option is checked, the foreign key is enforced. Table Constraints pane Specifies one or more check constraints for the table.

Name : Name of the check constraint definition. Enabled : If this option is checked, the check constraint is enforced. Comments pane Optional descriptive comments about the table.

Storage pane Enables you to specify storage options for the table. Tablespace : Name of the tablespace for the table or index. External Table Properties pane Specifies options for an external table, which is a read-only table whose metadata is stored in the database but whose data in stored outside the database. General On Pre-built Table : If Yes , an existing table is registered as a preinitialized materialized view. Refresh Clause Refresh : Select Yes to enable refresh operations.

Refresh Type : The method of refresh operation to be performed: Complete Refresh: Executes the defining query of the materialized view, even if a fast refresh is possible. With : Refresh type, which determines the type of materialized view: Primary Key: Creates a primary key materialized view, which allows materialized view master tables to be reorganized without affecting the eligibility of the materialized view for fast refresh.

Rollback Segment : Enter the name of the rollback segment. Enforced: Causes only enforced constraints to be used during the refresh operation. Output pane Displays the results of the DDL commands. You can create and edit in three ways: Right-click a table in the worksheet Navigator tab, and select Add Index. Definition pane Schema : Database schema that owns the table associated with the index.

Table : Name of the table associated with the index. Schema : Database in which to create the index. Tablespace : Tablespace for the index. Available Columns : Columns available in the table. Properties pane Schema : Database schema in which to create the sequence.

Name : Name of the sequence. Schema : Database schema in which to create the view. Name : Name of the view. Columns pane Click the Refresh Columns icon to automatically populate the columns in this pane. Storage pane Force on Create : Select Yes to create the view regardless of whether the base tables of the view or the referenced object types exist or the owner of the schema containing the view has privileges on them. Output Displays the results of the DDL commands.

The icons in this pane are: Clear output : Clears the output. In the Query Result tab, in the display table, the context menu right-click for the row header consists of the following: Columns enables you to select columns to hide. Note: If a popup blocker is enabled, it will prevent the file from downloading. Runs the code as query.

If your source worksheet or range doesn't include the names, it is a good idea to add them to the source before you start the import operation. Note: If you plan to append the data to an existing table, ensure that the name of each column exactly matches the name of the corresponding field. If the name of a column is different from the name of the corresponding field in the table, the import operation will fail.

To see the names of the fields, open the table in Design view in Access. Close the source workbook, if it is open. Keeping the source file open might result in data conversion errors during the import operation. Open the Access database where the imported data will be stored. Ensure that the database is not read-only, and that you have permissions to make changes to the database.

If you don't want to store the data in any of your existing databases, create a blank database. To do so:. Click the File tab, click New , and then click Blank Database. Before you start the import operation, decide whether you want to store the data in a new or existing table. Create a new table If you choose to store the data in a new table, Access creates a table and adds the imported data to this table.

If a table with the specified name already exists, Access overwrites the contents of the table with the imported data. Append to an existing table If you choose to add the data to an existing table, the rows in the Excel worksheet are appended to the specified table. Remember that most failures during append operations occur because the source data does not match the structure and field settings of the destination table.

To avoid this, open the destination table in Design view and review the following:. First row If the first row of the source worksheet or named range does not contain column headings, ensure that the position and data type of each column in the source worksheet matches those of the corresponding field in the table. If the first row contains column headings, the order of columns and fields do not need to match, but the name and data type of each column must exactly match those of its corresponding field.

Missing or extra fields If one or more fields in the source worksheet do not exist in the destination table, add them before you start the import operation. However, if the table contains fields that don't exist in the source, you do not need to delete those fields from the table if they accept null values. Tip: A field will accept null values if its Required property is set to No and its ValidationRule property setting doesn't prevent null values.

Primary key If the table contains a primary key field, the source worksheet or range must have a column that contains values that are compatible with the primary key field, and the imported key values must be unique.

If an imported record contains a primary key value that already exists in the destination table, the import operation displays an error message. Indexed fields If the Indexed property of a field in the table is set to Yes No Duplicates , the corresponding column in the source worksheet or range must contain unique values.

Choose the steps that match your Access version:. Note: The External Data tab is not available unless a database is open.

In the Get External Data - Excel Spreadsheet dialog box, in the File name box, specify the name of the Excel file that contains the data that you want to import. Click Browse and use the File Open dialog box to locate the file that you want to import. To store the data in a new table, select Import the source data into a new table in the current database. You will be prompted to name this table later.

To append the data to an existing table, select Append a copy of the records to the table and select a table from the drop-down list. This option is not available if the database has no tables. To link to the data source by creating a linked table, see the section Link to data in Excel , later in this article. The Import Spreadsheet Wizard starts, and leads you through the import process.

Go to the next set of steps. On the first page of the wizard, select the worksheet that contains the data that you want to import, and then click Next. On the second page of the wizard, click either Show Worksheets or Show Named Ranges , select either the worksheet or the named range that you want to import, and then click Next. If the first row of the source worksheet or range contains the field names, select First Row Contains Column Headings and click Next.

If you are importing the data into a new table, Access uses these column headings to name the fields in the table. You can change these names either during or after the import operation. If you are appending the data to an existing table, ensure that the column headings in the source worksheet exactly match the names of the fields in the destination table.

If you are appending data to an existing table, skip directly to step 6. If you are adding the data to a new table, follow the remaining steps. The wizard prompts you to review the field properties. Click a column in the lower half of the page to display the corresponding field's properties. Optionally, do any of the following:. Access reviews the first eight rows in each column to suggest the data type for the corresponding field.

If the column in the worksheet contains different types of values, such as text and numbers, in the first eight rows of a column, the wizard suggests a data type that is compatible with all the values in the column — most often, the text data type. Although you can choose a different data type, remember that values that are incompatible with the data type that you choose will be either ignored or converted incorrectly during the import process.

For more information about how to correct missing or incorrect values, see the section Troubleshoot missing or incorrect values , later in this article. To completely skip a source column, select the Do not import field Skip check box.

In the next screen, specify a primary key for the table. If you select Let Access add primary key , Access adds an AutoNumber field as the first field in the destination table, and automatically populates it with unique ID values, starting with 1.

Click Next. In the final wizard screen, specify a name for the destination table. In the Import to Table box, type a name for the table. If the table already exists, Access displays a prompt that asks whether you want to overwrite the existing contents of the table. Click Yes to continue or No to specify a different name for the destination table, and then click Finish to import the data.

If Access was able to import some or all the data, the wizard displays a page that shows you the status of the import operation. In addition, you can save the details of the operation for future use as a specification. Conversely, if the operation completely failed, Access displays the message An error occurred trying to import file.

Click Yes to save the details of the operation for future use. Saving the details helps you repeat the operation at a later time without having to step through the wizard each time. See Save the details of an import or export operation as a specification to learn how to save your save your specification details. See Run a saved import or export specification to learn how to run your saved import or link specifications.

See Schedule an import or export specification to learn how to schedule import and link tasks to run at specific times. If you receive the message An error occurred trying to import file , the import operation completely failed. Conversely, if the import operation displays a dialog box that prompts you to save the details of the operation, the operation was able to import all or some of the data. The status message also mentions the name of the error log table that contains the description of any errors that occurred during the import operation.

Important: Even if the status message indicates a completely successful operation, you should review the contents and structure of the table to ensure that everything looks correct before you start using the table. The following table describes the steps that you can take to correct missing or incorrect values. Tip: While you are troubleshooting the results, if you find just a few missing values, you can add them to the table manually.

Conversely, if you find that entire columns or a large number of values are either missing or were not imported properly, you should correct the problem in the source file.

After you have corrected all known problems, repeat the import operation. Graphical elements, such as logos, charts, and pictures cannot be imported. Manually add them to the database after completing the import operation. The results of a calculated column or cells are imported, but not the underlying formula. During the import operation, you can specify a data type that is compatible with the formula results, such as Number.

However, if the source worksheet or range includes a column that contains only -1 or 0 values, Access, by default, creates a numeric field for the column. When you import data to a new table or append data to an existing table, Access does not enable support for multiple values in a field, even if the source column contains a list of values separated by semicolon ;. The list of values is treated as a single value and is placed in a text field.

If data appears truncated in a column in the Access table, try increasing the width of the column in Datasheet view. If that doesn't resolve the issue, the data in a numeric column in Excel is too large for the field size of the destination field in Access. For example, the destination field might have the FieldSize property set to Byte in an Access database but the source data contains a value greater than Correct the values in the source file and try importing again.

You might have to set the Format property of certain fields in design view to ensure that the values are displayed correctly in Datasheet view. For example:. Long and medium dates might appear as short dates in Access. Note: If the source worksheet contains rich text formatting such as bold, underline, or italics, the text is imported, but the formatting is lost.

Records that you are importing might contain duplicate values that cannot be stored in the primary key field of the destination table or in a field that has the Indexed property set to Yes No Duplicates. Eliminate the duplicate values in the source file and try importing again. The date fields that are imported from an Excel worksheet might be off by four years. Excel for Windows uses the Date System in which serial numbers range from 1 to 65, , which correspond to the dates January 1, through December 31, However, Excel for the Macintosh uses the Date System in which serial numbers range from 0 to 63, , which correspond to the dates January 1, through December 31, You might see an error message at the end of the import operation about data that was deleted or lost during the operation, or when you open the table in Datasheet view, you might see that some field values are blank.

If the source columns in Excel are not formatted, or the first eight source rows contain values of different data types, open the source worksheet and do the following:.

Move the rows so that the first eight rows in each column do not contain values of different data types. We generally use spreadsheets for smaller sets of data, of which you can analyze the data and sort list items. The types of data storage which you would use spreadsheets for include inventory, statistical data modeling, and computing data. Databases are better for storing large amounts of raw data over a long period of time.

They are particularly useful if you have multiple users accessing the data at one time, as well as having constant data updates. Databases are powerful enough to maintain data integrity whilst carrying out simultaneous data inputs and updates. Although both databases and spreadsheets offer a variety of processing functions, databases offer a lot more complex functions that only more advanced users can carry out.

Spreadsheets are great for users with less technical experience, as most of the processing functions are automated. There is a long list of formulas you can input for specific results. Databases offer a wider range of data manipulation, however, this is only possible through programming or SQL code. These processes cannot be automated, so a vast knowledge of how to write this code is vital, in order to retrieve and manipulate tables of data.

In most cases, only one user can access spreadsheets at a time. There are exceptions to this, such as Google Sheets, which allow collaboration within the same spreadsheet file. Furthermore, spreadsheet programs have a fantastic range of visual analytical tools to present your data. These include graphs, charts, and maps that are automatically generated by the program for immediate results.

In contrast, one of the main characteristics of a database is that it can be accessed by numerous people at the same time. The DBMS ensures that no one can edit the same data value and at the same time, thus maintaining data integrity. However, presenting this data is not possible with a database. Usually, this is something that the application supporting the database would manage.

In any case, presenting data from a database requires more technological expertise.