return $sql;
}
- /**
- * Returns the code (in array) needed to add one comment to the table
- */
- function getCommentSQL ($xmldb_table) {
-
- $comment = "COMMENT ON TABLE " . $this->getEncQuoted($this->prefix . $xmldb_table->getName());
- $comment.= " IS '" . substr($xmldb_table->getComment(), 0, 250) . "'";
-
- return array($comment);
- }
-
- /**
- * Given one XMLDBTable and one XMLDBField, return the SQL statements needded to alter the field in the table
- * PostgreSQL has some severe limits:
- * - Any change of type or precision requires a new temporary column to be created, values to
- * be transfered potentially casting them, to apply defaults if the column is not null and
- * finally, to rename it
- * - Changes in null/not null require the SET/DROP NOT NULL clause
- * - Changes in default require the SET/DROP DEFAULT clause
- */
- function getAlterFieldSQL($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];
- print_object($metac);
- $oldtype = strtolower($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 : $metac->default_value;
- /// If field is CLOB and new one is also XMLDB_TYPE_TEXT or
- /// if fiels is BLOB and new one is also XMLDB_TYPE_BINARY
- /// prevent type to be specified, so only NULL and DEFAULT clauses are allowed
- if (($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, $xmldb_field);
- }
+ /**
+ * Returns the code (in array) needed to add one comment to the table
+ */
+ function getCommentSQL ($xmldb_table) {
+
+ $comment = "COMMENT ON TABLE " . $this->getEncQuoted($this->prefix . $xmldb_table->getName());
+ $comment.= " IS '" . substr($xmldb_table->getComment(), 0, 250) . "'";
+
+ return array($comment);
+ }
+
+ /**
+ * Given one XMLDBTable and one XMLDBField, return the SQL statements needded to alter the field in the table
+ * PostgreSQL has some severe limits:
+ * - Any change of type or precision requires a new temporary column to be created, values to
+ * be transfered potentially casting them, to apply defaults if the column is not null and
+ * finally, to rename it
+ * - Changes in null/not null require the SET/DROP NOT NULL clause
+ * - Changes in default require the SET/DROP DEFAULT clause
+ */
+ function getAlterFieldSQL($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;
+ $olddecimals = empty($metac->scale) ? null : $metac->scale;
+ $oldnotnull = empty($metac->not_null) ? false : $metac->not_null;
+ $olddefault = empty($metac->has_default) ? null : strtok($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')) {
+ $typechanged = false;
+ }
+ /// Detect if we are changing the precision
+ if (($xmldb_field->getType() == XMLDB_TYPE_TEXT) ||
+ ($xmldb_field->getType() == XMLDB_TYPE_BINARY) ||
+ ($oldlength == -1) ||
+ ($xmldb_field->getLength() == $oldlength)) {
+ $precisionchanged = false;
+ }
+ /// Detect if we are changing the decimals
+ if (($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)) {
+ $notnullchanged = false;
+ }
+
+ /// If the type or the precision or the decimals have changed, then we need to:
+ /// - create one temp column with the new specs
+ /// - fill the new column with the values from the old one (casting if needed)
+ /// - drop the old column
+ /// - rename the temp column to the original name
+ if ($typechanged || $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, $xmldb_field));
+ /// Detect some basic casting options
+ if ((substr($oldmetatype, 0, 1) == 'C' && $xmldb_field->getType() == XMLDB_TYPE_NUMBER) ||
+ (substr($oldmetatype, 0, 1) == 'C' && $xmldb_field->getType() == XMLDB_TYPE_FLOAT)) {
+ $copyorigin = 'CAST(CAST('.$fieldname.' AS TEXT) AS REAL)'; //From char to number or float
+ } else if ((substr($oldmetatype, 0, 1) == 'C' && $xmldb_field->getType() == XMLDB_TYPE_INTEGER)) {
+ $copyorigin = 'CAST(CAST('.$fieldname.' AS TEXT) AS INTEGER)'; //From char to integer
+ } else {
+ $copyorigin = $fieldname; //Direct copy between columns
+ }
+ /// Copy contents from original col to the temporal one
+ $results[] = 'UPDATE ' . $tablename . ' SET ' . $tempcolname . ' = ' . $copyorigin;
+ /// 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
+ $from_temp_fields = true;
+ }
+ /// If the default has changed or we have used one temp field
+ if ($defaultchanged || $from_temp_fields) {
+ if ($default_clause = $this->getDefaultClause($xmldb_field)) {
+ $results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' SET' . $default_clause; /// Add default clause
+ } else {
+ if (!$from_temp_fields) { /// Only drop default if we haven't used the temp field, i.e. old column
+ $results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' DROP DEFAULT'; /// Drop default clause
+ }
+ }
+ }
+ /// If the not null has changed or we have used one temp field
+ if ($notnullchanged || $from_temp_fields) {
+ if ($xmldb_field->getNotnull()) {
+ $results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' SET NOT NULL';
+ } else {
+ $results[] = 'ALTER TABLE ' . $tablename . ' ALTER COLUMN ' . $fieldname . ' DROP NOT NULL';
+ }
+ }
+
+ /// Return the results
+ return $results;
+ }
/**
* Returns an array of reserved words (lowercase) for this DB
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