org.h2.command.dml.SetClauseList Maven / Gradle / Ivy
/*
* Copyright 2004-2022 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.command.dml;
import java.util.ArrayList;
import org.h2.api.ErrorCode;
import org.h2.engine.SessionLocal;
import org.h2.expression.Expression;
import org.h2.expression.ExpressionList;
import org.h2.expression.ExpressionVisitor;
import org.h2.expression.Parameter;
import org.h2.expression.ValueExpression;
import org.h2.message.DbException;
import org.h2.result.LocalResult;
import org.h2.result.ResultTarget;
import org.h2.result.Row;
import org.h2.table.Column;
import org.h2.table.ColumnResolver;
import org.h2.table.DataChangeDeltaTable.ResultOption;
import org.h2.table.Table;
import org.h2.util.HasSQL;
import org.h2.value.Value;
import org.h2.value.ValueNull;
/**
* Set clause list.
*/
public final class SetClauseList implements HasSQL {
private final Table table;
private final UpdateAction[] actions;
private boolean onUpdate;
public SetClauseList(Table table) {
this.table = table;
actions = new UpdateAction[table.getColumns().length];
}
/**
* Add a single column.
*
* @param column the column
* @param expression the expression
*/
public void addSingle(Column column, Expression expression) {
int id = column.getColumnId();
if (actions[id] != null) {
throw DbException.get(ErrorCode.DUPLICATE_COLUMN_NAME_1, column.getName());
}
if (expression != ValueExpression.DEFAULT) {
actions[id] = new SetSimple(expression);
if (expression instanceof Parameter) {
((Parameter) expression).setColumn(column);
}
} else {
actions[id] = SetClauseList.UpdateAction.SET_DEFAULT;
}
}
/**
* Add multiple columns.
*
* @param columns the columns
* @param expression the expression (e.g. an expression list)
*/
public void addMultiple(ArrayList columns, Expression expression) {
int columnCount = columns.size();
if (expression instanceof ExpressionList) {
ExpressionList expressions = (ExpressionList) expression;
if (!expressions.isArray()) {
if (columnCount != expressions.getSubexpressionCount()) {
throw DbException.get(ErrorCode.COLUMN_COUNT_DOES_NOT_MATCH);
}
for (int i = 0; i < columnCount; i++) {
addSingle(columns.get(i), expressions.getSubexpression(i));
}
return;
}
}
if (columnCount == 1) {
// Row value special case
addSingle(columns.get(0), expression);
} else {
int[] cols = new int[columnCount];
RowExpression row = new RowExpression(expression, cols);
int minId = table.getColumns().length - 1, maxId = 0;
for (int i = 0; i < columnCount; i++) {
int id = columns.get(i).getColumnId();
if (id < minId) {
minId = id;
}
if (id > maxId) {
maxId = id;
}
}
for (int i = 0; i < columnCount; i++) {
Column column = columns.get(i);
int id = column.getColumnId();
cols[i] = id;
if (actions[id] != null) {
throw DbException.get(ErrorCode.DUPLICATE_COLUMN_NAME_1, column.getName());
}
actions[id] = new SetMultiple(row, i, id == minId, id == maxId);
}
}
}
boolean prepareUpdate(Table table, SessionLocal session, ResultTarget deltaChangeCollector,
ResultOption deltaChangeCollectionMode, LocalResult rows, Row oldRow,
boolean updateToCurrentValuesReturnsZero) {
Column[] columns = table.getColumns();
int columnCount = columns.length;
Row newRow = table.getTemplateRow();
for (int i = 0; i < columnCount; i++) {
UpdateAction action = actions[i];
Column column = columns[i];
Value newValue;
if (action == null || action == UpdateAction.ON_UPDATE) {
newValue = column.isGenerated() ? null : oldRow.getValue(i);
} else if (action == UpdateAction.SET_DEFAULT) {
newValue = !column.isIdentity() ? null : oldRow.getValue(i);
} else {
newValue = action.update(session);
if (newValue == ValueNull.INSTANCE && column.isDefaultOnNull()) {
newValue = !column.isIdentity() ? null : oldRow.getValue(i);
} else if (column.isGeneratedAlways()) {
throw DbException.get(ErrorCode.GENERATED_COLUMN_CANNOT_BE_ASSIGNED_1,
column.getSQLWithTable(new StringBuilder(), TRACE_SQL_FLAGS).toString());
}
}
newRow.setValue(i, newValue);
}
newRow.setKey(oldRow.getKey());
table.convertUpdateRow(session, newRow, false);
boolean result = true;
if (onUpdate) {
if (!oldRow.hasSameValues(newRow)) {
for (int i = 0; i < columnCount; i++) {
if (actions[i] == UpdateAction.ON_UPDATE) {
newRow.setValue(i, columns[i].getEffectiveOnUpdateExpression().getValue(session));
} else if (columns[i].isGenerated()) {
newRow.setValue(i, null);
}
}
// Convert on update expressions and reevaluate
// generated columns
table.convertUpdateRow(session, newRow, false);
} else if (updateToCurrentValuesReturnsZero) {
result = false;
}
} else if (updateToCurrentValuesReturnsZero && oldRow.hasSameValues(newRow)) {
result = false;
}
if (deltaChangeCollectionMode == ResultOption.OLD) {
deltaChangeCollector.addRow(oldRow.getValueList());
} else if (deltaChangeCollectionMode == ResultOption.NEW) {
deltaChangeCollector.addRow(newRow.getValueList().clone());
}
if (!table.fireRow() || !table.fireBeforeRow(session, oldRow, newRow)) {
rows.addRowForTable(oldRow);
rows.addRowForTable(newRow);
}
if (deltaChangeCollectionMode == ResultOption.FINAL) {
deltaChangeCollector.addRow(newRow.getValueList());
}
return result;
}
/**
* Check if this expression and all sub-expressions can fulfill a criteria.
* If any part returns false, the result is false.
*
* @param visitor
* the visitor
* @return if the criteria can be fulfilled
*/
boolean isEverything(ExpressionVisitor visitor) {
for (UpdateAction action : actions) {
if (action != null) {
if (!action.isEverything(visitor)) {
return false;
}
}
}
return true;
}
/**
* Map the columns and optimize expressions.
*
* @param session
* the session
* @param resolver1
* the first column resolver
* @param resolver2
* the second column resolver, or {@code null}
*/
void mapAndOptimize(SessionLocal session, ColumnResolver resolver1, ColumnResolver resolver2) {
Column[] columns = table.getColumns();
boolean onUpdate = false;
for (int i = 0; i < actions.length; i++) {
UpdateAction action = actions[i];
if (action != null) {
action.mapAndOptimize(session, resolver1, resolver2);
} else {
Column column = columns[i];
if (column.getEffectiveOnUpdateExpression() != null) {
actions[i] = UpdateAction.ON_UPDATE;
onUpdate = true;
}
}
}
this.onUpdate = onUpdate;
}
@Override
public StringBuilder getSQL(StringBuilder builder, int sqlFlags) {
Column[] columns = table.getColumns();
builder.append("\nSET\n ");
boolean f = false;
for (int i = 0; i < actions.length; i++) {
UpdateAction action = actions[i];
if (action != null && action != UpdateAction.ON_UPDATE) {
if (action.getClass() == SetMultiple.class) {
SetMultiple multiple = (SetMultiple) action;
if (multiple.first) {
if (f) {
builder.append(",\n ");
}
f = true;
RowExpression r = multiple.row;
builder.append('(');
int[] cols = r.columns;
for (int j = 0, l = cols.length; j < l; j++) {
if (j > 0) {
builder.append(", ");
}
columns[cols[j]].getSQL(builder, sqlFlags);
}
r.expression.getUnenclosedSQL(builder.append(") = "), sqlFlags);
}
} else {
if (f) {
builder.append(",\n ");
}
f = true;
Column column = columns[i];
if (action != UpdateAction.SET_DEFAULT) {
action.getSQL(builder, sqlFlags, column);
} else {
column.getSQL(builder, sqlFlags).append(" = DEFAULT");
}
}
}
}
return builder;
}
private static class UpdateAction {
static UpdateAction ON_UPDATE = new UpdateAction();
static UpdateAction SET_DEFAULT = new UpdateAction();
UpdateAction() {
}
Value update(SessionLocal session) {
throw DbException.getInternalError();
}
boolean isEverything(ExpressionVisitor visitor) {
return true;
}
void mapAndOptimize(SessionLocal session, ColumnResolver resolver1, ColumnResolver resolver2) {
// Do nothing
}
void getSQL(StringBuilder builder, int sqlFlags, Column column) {
throw DbException.getInternalError();
}
}
private static final class SetSimple extends UpdateAction {
private Expression expression;
SetSimple(Expression expression) {
this.expression = expression;
}
@Override
Value update(SessionLocal session) {
return expression.getValue(session);
}
@Override
boolean isEverything(ExpressionVisitor visitor) {
return expression.isEverything(visitor);
}
@Override
void mapAndOptimize(SessionLocal session, ColumnResolver resolver1, ColumnResolver resolver2) {
expression.mapColumns(resolver1, 0, Expression.MAP_INITIAL);
if (resolver2 != null) {
expression.mapColumns(resolver2, 0, Expression.MAP_INITIAL);
}
expression = expression.optimize(session);
}
@Override
void getSQL(StringBuilder builder, int sqlFlags, Column column) {
expression.getUnenclosedSQL(column.getSQL(builder, sqlFlags).append(" = "), sqlFlags);
}
}
private static final class RowExpression {
Expression expression;
final int[] columns;
Value[] values;
RowExpression(Expression expression, int[] columns) {
this.expression = expression;
this.columns = columns;
}
boolean isEverything(ExpressionVisitor visitor) {
return expression.isEverything(visitor);
}
void mapAndOptimize(SessionLocal session, ColumnResolver resolver1, ColumnResolver resolver2) {
expression.mapColumns(resolver1, 0, Expression.MAP_INITIAL);
if (resolver2 != null) {
expression.mapColumns(resolver2, 0, Expression.MAP_INITIAL);
}
expression = expression.optimize(session);
}
}
private static final class SetMultiple extends UpdateAction {
final RowExpression row;
private final int position;
boolean first;
private boolean last;
SetMultiple(RowExpression row, int position, boolean first, boolean last) {
this.row = row;
this.position = position;
this.first = first;
this.last = last;
}
@Override
Value update(SessionLocal session) {
Value[] v;
if (first) {
Value value = row.expression.getValue(session);
if (value == ValueNull.INSTANCE) {
throw DbException.get(ErrorCode.DATA_CONVERSION_ERROR_1, "NULL to assigned row value");
}
row.values = v = value.convertToAnyRow().getList();
if (v.length != row.columns.length) {
throw DbException.get(ErrorCode.COLUMN_COUNT_DOES_NOT_MATCH);
}
} else {
v = row.values;
if (last) {
row.values = null;
}
}
return v[position];
}
@Override
boolean isEverything(ExpressionVisitor visitor) {
return !first || row.isEverything(visitor);
}
@Override
void mapAndOptimize(SessionLocal session, ColumnResolver resolver1, ColumnResolver resolver2) {
if (first) {
row.mapAndOptimize(session, resolver1, resolver2);
}
}
}
}
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