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Required. Holds the data type of a column:

• BOOLEAN Does not require data-length or data-scale attributes. These attributes should not be specified. Implementation on all DBMSs:
  • CHAR(1) where T is the boolean TRUE value and F is FALSE.
• CHAR Requires data-length attribute. Implementation on all DBMSs:
  • CHAR(data-length)
• CLOB Requires data-length attribute. Implementation:
  • TEXT for Microsoft SQL Server
  • CLOB for Oracle
• DECIMAL Requires data-length (used for precision) and data-scale attributes. Implementation:
  • NUMBER(data-length, data-scale) for Microsoft SQL Server and IBM UDB Oracle
• FLOAT Requires data-length attribute. Implementation:
  • FLOAT(data-length) for Microsoft SQL Server
  • NUMBER without any parameters for Oracle
• INTEGER Requires data-length attribute. Implementation:
  • data-length less than three: TINYINT; data-length two-to-four: SMALLINT; data-length more than four: BIGINT for Microsoft SQL Server
  • NUMBER(data-length) for Oracle
• TIMESTAMP Does not require data-length or data-scale attributes. These attributes should not be specified. Implementation:
  • DATETIME for Microsoft SQL Server
  • TIME for Oracle
• UNIQUE INTEGER Does not require data-length or data-scale attributes. These attributes should not be specified. This is a data type for a unique integer whose values are generated automatically. Implementation:
  • IDENTITY for Microsoft SQL Server
  • NUMBER(20,0) for Oracle. In addition, a SEQUENCE and a TRIGGER BEFORE INSERT are created, which select the NEXTVAL of the SEQUENCE from DUAL.
• VARCHAR Requires the data-length attribute. Implementation:
  • VARCHAR(data-length) for Microsoft SQL Server
  • VARCHAR2(data-length) for Oracle
• VARBINARY Requires the data-length attribute. Implementation:
  • VARBINARY(data-length) for Microsoft SQL Server
  • RAW(data-length) for Oracle

Required only for the data types listed below. Specifies the column data length:

• CHAR 
• CLOB
• DECIMAL
• FLOAT
• INTEGER 
• VARCHAR
• VARBINARY 

Optional. Specifies the column default. Can have the following values:

• NULL if the column is nullable (null=TRUE).
• N/A if no default exists. If the attribute is omitted, this is the default.

A constant value that is equal to the column type:

• BOOLEAN TRUE or FALSE
• CHAR A textual constant, such as ABC CLOB; a textual constant, such as ABC DECIMAL; or a decimal point constant, such as 10.3
• FLOAT A floating point constant, such as 12E7
• INTEGER An integer constant, such as 27
• TIMESTAMP One of the following:
  • A timestamp constant of the format yyyy-mm-dd hh:mm:ss.fffffffff, which is jafa.sql.Timestamp’s format, such as 2020-02-20 23:07:35:175000000. Each DBMS displays a slightly different default. Implementation:
    • 2020-02-20 23:07:35:175 for Microsoft SQL Server
    • TO_DATE('2020-02-20 23:07:35') for Oracle
  • The literal string CURRENT TIMESTAMP. Implementation:
    • GETDATE() for Microsoft SQL Server
    • SYSDATE for Oracle
• UNIQUE INTEGER Default value not required and not allowed.
• VARCHAR A textual constant, such as ABC
• VARBINARY A hex string where every two hexadecimal digits represent one byte, such as A07C889F. Each DBMS displays a slightly different default. Implementation:
  • 0xA07C889F for Microsoft SQL Server
  • HEXTORAW('A07C889F') for Oracle

Required for the column role in columns of statistics tables. Can have the following values:

• IDENTIFIER A column identifying the sampled entity. The concatenation of all identifiers should uniquely identify the entity.
• DATE A column identifying the sampled period. Its type should be TIMESTAMP and be equal to the beginning of the sampled period.
• SUM A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by the SUM function.
• MIN A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by the MIN function.
• MAX A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by the MAX function.
• AVG A statistics column whose transfer to a higher summary level (such as hourly to daily) should be applied by the AVG function.