bps::SqlValues Class Reference

Convenience class to help composing select, insert and update statements. More...

Public Member Functions
void	clear ()
	Clear the list.
void	insert (String aKey, Mixed aValue)
	Insert a key/value pair.
Number	remove (String aKey)
	Removes the value with the given key.
	SqlValues ()
	Default constructor.
String	toString () const
Mixed	value (String aName)
	Get the named columns value.

Properties
String	columns
	The column names as comma separated list.
String	condPairs
	Pairs of "column=?", "column is null" or "(column is null or column='')" respectively as "and" separated list, as used for select conditions.
Boolean	isEmpty
	True if there are no columns.
Array	keys
	List of the keys.
Object	object
	The internal object holding the values.
String	pairs
	Pairs of "column=?" or "column=null" respectively as comma separated list, as used for update statements.
String	tags
	The value placeholders as comma separated list.
Array	values
	List of the values.

Detailed Description

Convenience class to help composing select, insert and update statements.

Empty strings are handled like NULL in context of inserts and updates. In select conditions the database column is compared to both, NULL or '', if the string value is empty. This special handling is necessary because for Oracle NULL and '' are the same, however for PostgreSQL they are not.

var vals = new bps.SqlValues;
vals.insert('c_x', 123);        // non-null example value
vals.insert('c_y', null);       // null example value
vals.insert('c_z', '');         // empty strings also handled like NULL

// select condition example
q.prepare(
    String("select c_foo from t_table where %1").arg(vals.condPairs)
    // select c_foo from t_table where c_x=? and c_y is null and (c_z is null or c_z='') 
);
q.execute(vals.values);  // 123

// update example
q.prepare(
    String("update t_table set %1 where c_key=?").arg(vals.pairs)
    // update t_table set c_x=?, c_y=null, c_z=null where c_key=? 
);
q.execute(vals.values.concat(456)); // 123 456

// insert example
q.prepare(
    String("insert into t_table (%1) values (%2)")
        .arg(vals.columns)
        .arg(vals.tags)
    // insert into t_table (c_x, c_y, c_z) values (?, null, null)
);
q.execute(vals.values); // 123

Member Function Documentation

void bps::SqlValues::insert	(	String	aKey,
		Mixed	aValue
	)

Insert a key/value pair.

Parameters

[in]	aKey	The key to insert
[in]	aValue	The value to insert

Number bps::SqlValues::remove

(

String

aKey

)

Removes the value with the given key.

Parameters

[in]

aKey

The key of the pair to remove.

Returns

Number of items removed which is usually 1 but will be 0 if the key isn't in the map.

String bps::SqlValues::toString

(

)

const

Returns

Returns "SqlValues(key=val, key2=val2, ...)"

Mixed bps::SqlValues::value

(

String

aName

)

Get the named columns value.

Parameters

[in]

aName

Name of the column to get the value for.

Returns

The value, or null in case no such column name is found.