MetaData Objects |
Active Web |
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MetaData Objects |
Active Web |
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A MetaData object can not be created, it can only be obtained from the Cursor object.
var cursor = db.cursor(“select * from myTable”);
var metaDataObj = cursor.getMetaData();
The MetaData object can be used to get information about the types and properties of the columns in a table that has been the subject of an SQL select using the Cursor object.
Shown below is the MetaData object prototype chain.
MetaData objects are of class MetaData.
The MetaData object properties are read only objects, one for each column in the cursor data. The property name is the column label and the column objects have properties that describe the column.
The table below describes all the properties that the columns may have. If the database does not return a certain metadata property then it will not be represented in the object.
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Property |
Description |
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catalogName |
The designated column's table's catalog name. |
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className |
The fully-qualified name of the Java class related to the column type. |
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displaySize |
Indicates the designated column's normal maximum width in characters. |
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columnLabel |
The designated columns's suggested title for use in printouts and displays. |
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columnTypeName |
The designated column's database-specific type name. |
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precision |
The designated column's number of decimal digits. |
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scale |
The designated column's number of digits to the right of the decimal point. |
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schemaName |
The designated column's table's schema. |
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tableName |
The designated column's table name. |
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isAutoIncrement |
Indicates whether the designated column is automatically numbered, thus read-only. |
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isCaseSensitive |
Indicates whether a column's case matters. |
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isCurrency |
Indicates whether the designated column is a cash value. |
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isDefinitelyWritable |
Indicates whether a write on the designated column will definitely succeed |
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isNullable |
Indicates the nullability of values in the designated column. |
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isReadOnly |
Indicates whether the designated column is definitely not writable. |
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isSearchable |
Indicates whether the designated column can be used in a where clause. |
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isSigned |
Indicates whether values in the designated column are signed numbers. |
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isWritable |
Indicates whether it is possible for a write on the designated column to succeed. |
The example below can be used to find out if a column with a label of 'myColumn1' is writable:
var cursor = db.cursor(“select * from myTable”);
var metaDataObj = cursor.getMetaData();
var column1Writable = metaDataObj.myColumn1.isWritable;
The MetaData object has no functions.
Topic ID: 150072