1 alias

Allows you to set an alias to a column or expression.

<alias name='name'/>

Attributes
Name	Type	Required	Default	Description
Aname	string				Alias name.

Example

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COUNT(*) <alias name='num_registros'/>

2 matches

<matches>
    <expresion /> *
</matches>

Arguments
Name	Type	Required	Unique	Nullable	Description
Eexpresion	string				Tag content must be enclosed in single quotes.

Example

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<matches>'M*'</matches>

3 regexp

<regexp>
    <reg-col /> !
    <reg-expr /> !
</regexp>

Arguments
Name	Type	Required	Unique	Nullable	Description
Ereg-col	string				A character expression, such as a character column.
Ereg-expr	string				A character expression. The following escape wildcards are accepted: * : Matches any string of zero or more characters. ? : Matches the previous element 0 or 1 times. . : Matches any single character. [ . . . ] : Matches any of the enclosed characters, including ranges, as in [a-z]. If there is any space character inside, it will be removed for compatibility purposes. [^ . . . ] : Matches any character except form the enclosed ones, including ranges, as in [a-z]. If there is any space character inside, it will be removed for compatibility purposes. { m , n } : Matches the previous element from m to n times. { m } : Matches the previous element exactly m times. \ : Escape character.

CHAR type

CHAR type may have fixed size, that is, CHAR(4) will occuppy 4 characters even if its inserted content is only 'A', one character. This may interfere with regexp correct functioning.

3.1 Examples

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Table creation and insertions.

CREATE TABLE test_regexp (
    a char(4)
);

INSERT INTO test_regexp(a) VALUES ('A');
INSERT INTO test_regexp(a) VALUES ('AB');
INSERT INTO test_regexp(a) VALUES ('*?');
INSERT INTO test_regexp(a) VALUES ('?*')
INSERT INTO test_regexp(a) VALUES ('AAA');
INSERT INTO test_regexp(a) VALUES ('X');  -- will not match

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Example 1

<select>
    <columns>
		COUNT(*)
    </columns>
    <from table='test_regexp'  />
    <where>
    	<regexp>
            <reg-col>a</reg-col>
            <!-- 'A' 0 or 1 times -->
            <reg-expr>'A?'</reg-expr>
        </regexp>
	</where>
</select>

1   -- AB

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Example 2

<select>
    <columns>
		COUNT(*)
    </columns>
    <from table='test_regexp'  />
    <where>
    	<regexp>
            <reg-col>a</reg-col>
            <!-- 0 or more characters + 'A' + 0 or more characters -->
            <reg-expr>'*A*'</reg-expr>
        </regexp>
	</where>
</select>

3   -- A, AB, AAA

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Example 3

<select>
    <columns>
		COUNT(*)
    </columns>
    <from table='test_regexp'  />
    <where>
    	<regexp>
            <reg-col>a</reg-col>
            <-- 1 to 3 consecutive 'A' -->
            <reg-expr>'A{1,3}'</reg-expr>
        </regexp>
	</where>
</select>

2   -- A, AAA

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Example 4

<select>
    <columns>
		COUNT(*)
    </columns>
    <from table='test_regexp'  />
    <where>
    	<regexp>
            <reg-col>a</reg-col>
            <!-- 'B' preceded by a character that must not be 'A'
            <reg-expr>'[^A]B'</reg-expr>
        </regexp>
	</where>
</select>

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Example 5

<select>
    <columns>
		COUNT(*)
    </columns>
    <from table='test_regexp'  />
    <where>
    	<regexp>
            <reg-col>a</reg-col>
            <!-- '*' + a single character + 0 or more characters -->
            <reg-expr>'\*.*'</reg-expr>
        </regexp>
	</where>
</select>

1   -- *?

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Example 6

<select>
    <columns>
		COUNT(*)
    </columns>
    <from table='test_regexp'  />
    <where>
    	<regexp>
            <reg-col>a</reg-col>
            <!-- 2 characters that must be '*' or '?' --> 
            <reg-expr>'[\*\?]{2}'</reg-expr>
        </regexp>
	</where>
</select>

2   -- *?, ?*

4 rowid

Allows retrieving the name of the unique identifier (rowid) of a row in a table.

<rowid table='table'/>

Attributes
Name	Type	Required	Default	Description
Atable	string				Table name.

Example

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<rowid table='gcompedh'/>

5 user

Retrieve the name of the database session user.

<user />

Example

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<user/>

Miscellaneous Functions

1 alias

2 matches

3 regexp

CHAR type

3.1 Examples

4 rowid

5 user