* Oracle has some severe limits:
* - clob and blob fields doesn't allow type to be specified
* - error is dropped if the null/not null clause is specified and hasn't changed
+ * - changes in precision/decimals of numeric fields drop an ORA-1440 error
*/
function getAlterFieldSQL($xmldb_table, $xmldb_field) {
- global $db;
-
- /// Get the quoted name of the table and field
- $tablename = $this->getEncQuoted($this->prefix . $xmldb_table->getName());
- $fieldname = $this->getEncQuoted($xmldb_field->getName());
-
- /// Take a look to field metadata
- $meta = array_change_key_case($db->MetaColumns($tablename));
- $metac = $meta[$fieldname];
- $oldtype = strtolower($metac->type);
- $oldlength = $metac->max_length;
- $olddecimals = empty($metac->scale) ? null : $metac->scale;
- $oldnotnull = empty($metac->not_null) ? false : $metac->not_null;
- $olddefault = empty($metac->default_value) ? null : $metac->default_value;
-
- $islob = false;
-
- /// If field is CLOB and new one is also XMLDB_TYPE_TEXT or
- /// if fiels is BLOB and new one is also XMLDB_TYPE_BINARY
- /// prevent type to be specified, so only NULL and DEFAULT clauses are allowed
- if (($oldtype = 'clob' && $xmldb_field->getType() == XMLDB_TYPE_TEXT) ||
- ($oldtype = 'blob' && $xmldb_field->getType() == XMLDB_TYPE_BINARY)) {
- $this->alter_column_skip_type = true;
- $islob = true;
- }
-
- /// If field is NOT NULL and the new one too or
- /// if field is NULL and the new one too
- /// prevent null clause to be specified
- if (($oldnotnull && $xmldb_field->getNotnull()) ||
- (!$oldnotnull && !$xmldb_field->getNotnull())) {
- $this->alter_column_skip_notnull = true;
- }
-
- /// In the rest of cases, use the general generator
- return parent::getAlterFieldSQL($xmldb_table, $xmldb_field);
+ global $db;
+
+ $results = array(); /// To store all the needed SQL commands
+
+ /// Get the quoted name of the table and field
+ $tablename = $this->getEncQuoted($this->prefix . $xmldb_table->getName());
+ $fieldname = $this->getEncQuoted($xmldb_field->getName());
+
+ /// Take a look to field metadata
+ $meta = array_change_key_case($db->MetaColumns($tablename));
+ $metac = $meta[$fieldname];
+ $oldtype = strtolower($metac->type);
+ $oldmetatype = column_type($xmldb_table->getName(), $fieldname);
+ $oldlength = $metac->max_length;
+ /// To calculate the oldlength if the field is numeric, we need to perform one extra query
+ /// because ADOdb has one bug here. http://phplens.com/lens/lensforum/msgs.php?id=15883
+ if ($oldmetatype == 'N') {
+ $uppertablename = strtoupper($tablename);
+ $upperfieldname = strtoupper($fieldname);
+ if ($col = get_record_sql("SELECT cname, precision
+ FROM col
+ WHERE tname = '$uppertablename'
+ AND cname = '$upperfieldname'")) {
+ $oldlength = $col->precision;
+ }
+ }
+ $olddecimals = empty($metac->scale) ? null : $metac->scale;
+ $oldnotnull = empty($metac->not_null) ? false : $metac->not_null;
+ $olddefault = empty($metac->default_value) ? null : $metac->default_value;
+
+ $typechanged = true; //By default, assume that the column type has changed
+ $precisionchanged = true; //By default, assume that the column precision has changed
+ $decimalchanged = true; //By default, assume that the column decimal has changed
+ $defaultchanged = true; //By default, assume that the column default has changed
+ $notnullchanged = true; //By default, assume that the column notnull has changed
+
+ $from_temp_fields = false; //By default don't assume we are going to use temporal fields
+
+ /// Detect if we are changing the type of the column
+ if (($xmldb_field->getType() == XMLDB_TYPE_INTEGER && substr($oldmetatype, 0, 1) == 'I') ||
+ ($xmldb_field->getType() == XMLDB_TYPE_NUMBER && $oldmetatype == 'N') ||
+ ($xmldb_field->getType() == XMLDB_TYPE_FLOAT && $oldmetatype == 'F') ||
+ ($xmldb_field->getType() == XMLDB_TYPE_CHAR && substr($oldmetatype, 0, 1) == 'C') ||
+ ($xmldb_field->getType() == XMLDB_TYPE_TEXT && substr($oldmetatype, 0, 1) == 'X') ||
+ ($xmldb_field->getType() == XMLDB_TYPE_BINARY && $oldmetatype == 'B')) {
+ $typechanged = false;
+ }
+ /// Detect if precision has changed
+ if (($xmldb_field->getType() == XMLDB_TYPE_TEXT) ||
+ ($xmldb_field->getType() == XMLDB_TYPE_BINARY) ||
+ ($oldlength == -1) ||
+ ($xmldb_field->getLength() == $oldlength)) {
+ $precisionchanged = false;
+ }
+ /// Detect if decimal has changed
+ if (($xmldb_field->getType() == XMLDB_TYPE_INTEGER) ||
+ ($xmldb_field->getType() == XMLDB_TYPE_CHAR) ||
+ ($xmldb_field->getType() == XMLDB_TYPE_TEXT) ||
+ ($xmldb_field->getType() == XMLDB_TYPE_BINARY) ||
+ (!$xmldb_field->getDecimals()) ||
+ (!$olddecimals) ||
+ ($xmldb_field->getDecimals() == $olddecimals)) {
+ $decimalchanged = false;
+ }
+ /// Detect if we are changing the default
+ if (($xmldb_field->getDefault() === null && $olddefault === null) ||
+ ($xmldb_field->getDefault() === $olddefault) || //Check both equality and
+ ("'" . $xmldb_field->getDefault() . "'" === $olddefault)) { //Equality with quotes because ADOdb returns the default with quotes
+ $defaultchanged = false;
+ }
+ /// Detect if we are changing the nullability
+ if (($xmldb_field->getNotnull() === $oldnotnull)) {
+ $notnullchanged = false;
+ }
+
+ /// If type has changed or precision or decimal has changed and we are in one numeric field
+ /// - create one temp column with the new specs
+ /// - fill the new column with the values from the old one
+ /// - drop the old column
+ /// - rename the temp column to the original name
+ if (($typechanged) || ($oldmetatype == 'N' && ($precisionchanged || $decimalchanged))) {
+ $tempcolname = $xmldb_field->getName() . '_alter_column_tmp';
+ /// Prevent temp field to have both NULL/NOT NULL and DEFAULT constraints
+ $this->alter_column_skip_notnull = true;
+ $this->alter_column_skip_default = true;
+ $xmldb_field->setName($tempcolname);
+ /// Create the temporal column
+ $results = array_merge($results, $this->getAddFieldSQL($xmldb_table, $xmldb_field));
+ /// Copy contents from original col to the temporal one
+ $results[] = 'UPDATE ' . $tablename . ' SET ' . $tempcolname . ' = ' . $fieldname;
+ /// Drop the old column
+ $xmldb_field->setName($fieldname); //Set back the original field name
+ $results = array_merge($results, $this->getDropFieldSQL($xmldb_table, $xmldb_field));
+ /// Rename the temp column to the original one
+ $results[] = 'ALTER TABLE ' . $tablename . ' RENAME COLUMN ' . $tempcolname . ' TO ' . $fieldname;
+ /// Mark we have performed one change based in temp fields
+ $from_temp_fields = true;
+ /// Re-enable the notnull and default sections so the general AlterFieldSQL can use it
+ $this->alter_column_skip_notnull = false;
+ $this->alter_column_skip_default = false;
+ /// Dissavle the type section because we have done it with the temp field
+ $this->alter_column_skip_type = true;
+ }
+
+ /// If type and precision and decimals hasn't changed, prevent the type clause
+ if (!$typechanged && !$precisionchanged && !$decimalchanged) {
+ $this->alter_column_skip_type = true;
+ }
+
+ /// If NULL/NOT NULL hasn't changed
+ /// prevent null clause to be specified
+ if (!$notnullchanged) {
+ $this->alter_column_skip_notnull = true; /// Initially, prevent the notnull clause
+ /// But, if we have used the temp field and the new field is not null, then enforce the not null clause
+ if ($from_temp_fields && $xmldb_field->getNotnull()) {
+ $this->alter_column_skip_notnull = false;
+ }
+ }
+ /// If default hasn't changed
+ /// prevent default clause to be specified
+ if (!$defaultchanged) {
+ $this->alter_column_skip_default = true; /// Initially, prevent the default clause
+ /// But, if we have used the temp field and the new field has default clause, then enforce the default clause
+ if ($from_temp_fields && $default_clause = $this->getDefaultClause($xmldb_field)) {
+ $this->alter_column_skip_default = false;
+ }
+ }
+
+ /// If arriving here, something is not being skiped (type, notnull, default), calculate the standar AlterFieldSQL
+ if (!$this->alter_column_skip_type || !$this->alter_column_skip_notnull || !$this->alter_column_skip_default) {
+ $results = array_merge($results, parent::getAlterFieldSQL($xmldb_table, $xmldb_field));
+ return $results;
+ }
+
+ /// Finally return results
+ return $results;
}
/**
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