Null Conditions → A NULL condition tests for s. This is the only condition that you should use to test for s … . _conditions::= Description of the illustration _conditions.gif Table 6-9 lists the … conditions. Table 6-9 Null Conditions Type of Condition Operation Example IS [NOT] NULL Tests for s … . See Also: "Nulls " SELECT
NULL Statement → The NULL statement is a no-op: it passes control to the next statement without doing anything. In … the body of an IF-THEN clause, a loop, or a procedure, the NULL statement serves as a placeholder … . For more information, see "Using the NULL Statement". Syntax Description of the illustration … _statement.gif Usage Notes The
Handling Null/Not Null Datatypes → For every select-list column (not expression), DESCRIBE SELECT LIST returns a /not … constrained to be not , the high-order bit of SELT(J) is clear; otherwise, it is set.
15.4.3 Handling NULL/Not NULL Datatypes → For every select-list column (not expression), DESCRIBE SELECT LIST returns a NULL/not NULL … to be not NULL, the high-order bit of T[ i ] is clear; otherwise, it is set. Before using the … datatype in an OPEN or FETCH statement, if the NULL/not NULL bit is set, you must clear it. (Never set the
5.2.6 Handling NULL/NOT NULL Datatypes → DESCRIBE returns a NULL/NOT NULL indication in the SQLDVTYP element of the select descriptor … , defined as a FIXED BINARY (15). If a column is declared to be NOT NULL, the high-order bit of the … NULL/NOT NULL bit is set, you must clear it. (Never set the bit.) You can use the library procedure
11.4.4 Handling NULL/Not NULL Datatypes → For every select-list column (not expression), DESCRIBE SELECT LIST returns a NULL/not NULL … be not NULL, the high-order bit of SELDVTYP(J) datatype variable is clear; otherwise, it is set … . Before using the datatype in an OPEN or FETCH statement, if the NULL status bit is set, you must clear … it. Never set
19.2.6 NULL Indicator Structs → corresponding NULL indicator struct. When an object type is selected into a C struct, NULL indicator … information can be selected into a parallel struct. For example, the following NULL indicator struct was … ; OCIInd the_raw; }; typedef struct many_types_ind many_types_ind; The layout of the NULL struct is
Using the NULL Statement → The NULL statement does nothing, and passes control to the next statement. (Some languages refer to … such an instruction as a no-op.) You can use the NULL statement to indicate that you are aware of … a possibility, but no action is necessary. In the following example, the NULL statement shows that … ROLLBACK; WHEN VALUE_ERROR
Null Indicator Structs → corresponding NULL indicator struct. When an object type is selected into a C struct, NULL indicator … information may be selected into a parallel struct. For example, the following NULL indicator struct was … ; OCIInd the_raw; }; typedef struct many_types_ind many_types_ind; The layout of the NULL struct is
Null and Truncated Data → () methods of the ResultSet class or Statement class is or truncated. However, this behavior can … or truncated. The default behavior is to not raise an SQLException. In this case, data is … returned as zero ( 0 ) for numeric values and strings for character values. For data retrieved … Table 2-1, Table 2-2,
updateXML() and NULL Values → If you update an XML element to NULL, Oracle Database removes the attributes and children of the … . A NULL value for an element update is equivalent to setting the element to empty. If you update the … text node of an element to NULL, Oracle Database removes the text value of the element, and the … , and the text() node for the
Null Objects and Attributes → A table column, object attribute, collection, or collection element is NULL if it has been … initialized to NULL or has not been initialized at all. Usually, a NULL value is replaced by an actual value … later on. An object whose value is NULL is called atomically . An atomically object
NOT NULL Integrity Constraints → By default, all columns in a table allow s. Null means the absence of a value. A NOT NULL … constraint requires a column of a table contain no values. For example, you can define a NOT NULL … table. Figure 21-2 illustrates a NOT NULL integrity constraint. Figure 21-2 NOT NULL Integrity
17.2.1 NULL Indicators → C structures representing the NULL status of object types are generated by the Object Type … . Other Oracle types do not require special treatment for NULL indicators. Se Also: " Datatypes and … Host Variables" for more information about NULL indicators. Because object types have internal … structure, NULL indicators
Using NOT NULL → Besides assigning an initial value, declarations can impose the NOT NULL constraint: DECLARE … acct_id INTEGER(4) NOT NULL:= 9999; You cannot assign s to a variable defined as NOT NULL. If you try … , PL/SQL raises the predefined exception VALUE_ERROR. The NOT NULL constraint must be followed by an … NULL.
NULL Indicator Structure → If a column in a row of a database table has no value, then that column is said to be NULL, or to … contain a NULL. Two different types of NULLs can apply to objects: Any attribute of an object can … have a NULL value. This indicates that the value of that attribute of the object is not known. An … object instance may be atomically
SET NULL text → Sets the text displayed whenever a value occurs in the result of a SQL SELECT command. Use the … NULL clause of the COLUMN command to override the setting of the NULL variable for a given column. The default output for a is blank ("").
Specifying Null Values for Objects → Specifying values for nonscalar datatypes is somewhat more complex than for scalar datatypes … . An object can have a subset of its attributes be , it can have all of its attributes be (an … attributively object), or it can be itself (an atomically object). Specifying … field
11.1.2 Converting SQL NULL Data → Java represents a SQL NULL datum by the Java value . Java datatypes fall into two categories … cannot represent . Instead, they store the as the value zero (as defined by the JDBC … types can represent . The Java language defines an object wrapper type corresponding to every … primitive type