Eine Einführung in
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| SQLite | ||
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A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to SQLite | ||
| none | ||
| DB2 | ||
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A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to DB2 | ||
| We must explicitly state that the components are NOT NULL. | ||
| MS Access | ||
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A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to MS Access | ||
| none | ||
| PostgreSQL | ||
|
A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to PostgreSQL | ||
| none | ||
| Oracle | ||
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A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to Oracle | ||
| none | ||
| MS SQL Server | ||
|
A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to MS SQL Server | ||
| We must explicitly state that the components are NOT NULL. | ||
| MySQL | ||
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A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to MySQL | ||
| We must explicitly state that the components are NOT NULL. | ||
| Sybase | ||
|
A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to Sybase | ||
| We must explicitly state that the components are NOT NULL. | ||
| Mimer SQL | ||
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A composite key has more than one attribute (field). In this example we store details of tracks on albums - we need to use three columns to get a unique key - each album may have more than one disk - each disk will have tracks numbered 1, 2, 3... The primary key must be different for each row of the table. The primary key may not contain a null. | ||
| Specific to Mimer SQL | ||
| none | ||