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提交 3e77d2fb authored 作者: Noel Grandin's avatar Noel Grandin
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couple of cleanups to the CTE merge

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h2/src/docsrc/html/changelog.html
浏览文件 @ 3e77d2fb
......@@ -21,6 +21,8 @@ Change Log
<h2>Next Version (unreleased)</h2>
<ul>
<li>Issue#479 Allow non-recursive CTEs (WITH statements), patch from stumc
</li>
<li>Fix startup issue when using "CHECK" as a column name.
</li>
<li>Issue #423: ANALYZE performed multiple times on one table during execution of the same statement.
......
h2/src/main/org/h2/command/Parser.java
浏览文件 @ 3e77d2fb
......@@ -18,7 +18,6 @@ import java.util.Comparator;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import org.h2.api.ErrorCode;
import org.h2.api.Trigger;
import org.h2.command.ddl.AlterIndexRename;
......@@ -4857,97 +4856,99 @@ public class Parser {
}
private Query parseWith() {
List<TableView> viewsCreated = new ArrayList<TableView>();
readIf("RECURSIVE");
do{
viewsCreated.add(parseSingleCommonTableExpression());
} while(readIf(","));
List<TableView> viewsCreated = new ArrayList<TableView>();
readIf("RECURSIVE");
do {
viewsCreated.add(parseSingleCommonTableExpression());
} while (readIf(","));
Query q = parseSelectUnion();
q.setPrepareAlways(true);
return q;
}
private TableView parseSingleCommonTableExpression() {
String tempViewName = readIdentifierWithSchema();
Schema schema = getSchema();
Table recursiveTable;
ArrayList<Column> columns = New.arrayList();
String[] cols = null;
// column names are now optional - they can be inferred from the named
// query if not supplied
if(readIf("(")){
cols = parseColumnList();
for (String c : cols) {
// we dont really know the type of the column, so string will have to do
columns.add(new Column(c, Value.STRING));
}
}
Table old = session.findLocalTempTable(tempViewName);
if (old != null) {
if (!(old instanceof TableView)) {
throw DbException.get(ErrorCode.TABLE_OR_VIEW_ALREADY_EXISTS_1,
tempViewName);
}
TableView tv = (TableView) old;
if (!tv.isTableExpression()) {
throw DbException.get(ErrorCode.TABLE_OR_VIEW_ALREADY_EXISTS_1,
tempViewName);
}
session.removeLocalTempTable(old);
}
// this table is created as a work around because recursive
// table expressions need to reference something that look like themselves
// to work (its removed after creation in this method)
CreateTableData data = new CreateTableData();
data.id = database.allocateObjectId();
data.columns = columns;
data.tableName = tempViewName;
data.temporary = true;
data.persistData = true;
data.persistIndexes = false;
data.create = true;
data.session = session;
recursiveTable = schema.createTable(data);
session.addLocalTempTable(recursiveTable);
String querySQL;
List<Column> columnTemplateList = new ArrayList<Column>();
try {
read("AS");
read("(");
Query withQuery = parseSelect();
read(")");
withQuery.prepare();
querySQL = StringUtils.cache(withQuery.getPlanSQL());
ArrayList<Expression> withExpressions = withQuery.getExpressions();
for (int i = 0; i < withExpressions.size(); ++i) {
String columnName = cols != null ? cols[i] : withExpressions.get(i).getColumnName();
columnTemplateList.add(new Column(columnName, withExpressions.get(i).getType()));
}
} finally {
session.removeLocalTempTable(recursiveTable);
}
int id = database.allocateObjectId();
boolean isRecursive = true;
TableView view = null;
do{
view = new TableView(schema, id, tempViewName, querySQL,
parameters, columnTemplateList.toArray(new Column[0]), session,
isRecursive);
if(view.isRecursiveQueryDetected()!=isRecursive){
isRecursive = view.isRecursiveQueryDetected();
view = null;
continue;
}
} while(view==null);
view.setTableExpression(true);
view.setTemporary(true);
session.addLocalTempTable(view);
view.setOnCommitDrop(true);
return view;
}
private TableView parseSingleCommonTableExpression() {
String tempViewName = readIdentifierWithSchema();
Schema schema = getSchema();
Table recursiveTable;
ArrayList<Column> columns = New.arrayList();
String[] cols = null;
// column names are now optional - they can be inferred from the named
// query if not supplied
if (readIf("(")) {
cols = parseColumnList();
for (String c : cols) {
// we dont really know the type of the column, so string will
// have to do
columns.add(new Column(c, Value.STRING));
}
}
Table old = session.findLocalTempTable(tempViewName);
if (old != null) {
if (!(old instanceof TableView)) {
throw DbException.get(ErrorCode.TABLE_OR_VIEW_ALREADY_EXISTS_1,
tempViewName);
}
TableView tv = (TableView) old;
if (!tv.isTableExpression()) {
throw DbException.get(ErrorCode.TABLE_OR_VIEW_ALREADY_EXISTS_1,
tempViewName);
}
session.removeLocalTempTable(old);
}
// this table is created as a work around because recursive
// table expressions need to reference something that look like
// themselves
// to work (its removed after creation in this method)
CreateTableData data = new CreateTableData();
data.id = database.allocateObjectId();
data.columns = columns;
data.tableName = tempViewName;
data.temporary = true;
data.persistData = true;
data.persistIndexes = false;
data.create = true;
data.session = session;
recursiveTable = schema.createTable(data);
session.addLocalTempTable(recursiveTable);
String querySQL;
List<Column> columnTemplateList = new ArrayList<Column>();
try {
read("AS");
read("(");
Query withQuery = parseSelect();
read(")");
withQuery.prepare();
querySQL = StringUtils.cache(withQuery.getPlanSQL());
ArrayList<Expression> withExpressions = withQuery.getExpressions();
for (int i = 0; i < withExpressions.size(); ++i) {
String columnName = cols != null ? cols[i]
: withExpressions.get(i).getColumnName();
columnTemplateList.add(new Column(columnName,
withExpressions.get(i).getType()));
}
} finally {
session.removeLocalTempTable(recursiveTable);
}
int id = database.allocateObjectId();
// No easy way to determine if this is a recursive query up front, so we just compile
// it twice - once without the flag set, and if we didn't see a recursive term,
// then we just compile it again.
TableView view = new TableView(schema, id, tempViewName, querySQL,
parameters, columnTemplateList.toArray(new Column[0]), session,
true/* recursive */);
if (!view.isRecursiveQueryDetected()) {
view = new TableView(schema, id, tempViewName, querySQL, parameters,
columnTemplateList.toArray(new Column[0]), session,
false/* recursive */);
}
view.setTableExpression(true);
view.setTemporary(true);
session.addLocalTempTable(view);
view.setOnCommitDrop(true);
return view;
}
private CreateView parseCreateView(boolean force, boolean orReplace) {
boolean ifNotExists = readIfNotExists();
......
h2/src/main/org/h2/table/TableView.java
浏览文件 @ 3e77d2fb
......@@ -57,7 +57,7 @@ public class TableView extends Table {
private Query topQuery;
private ResultInterface recursiveResult;
private boolean tableExpression;
private boolean isRecursiveQueryDetected;
private boolean isRecursiveQueryDetected;
public TableView(Schema schema, int id, String name, String querySQL,
ArrayList<Parameter> params, Column[] columnTemplates, Session session,
......@@ -205,13 +205,12 @@ public class TableView extends Table {
} catch (DbException e) {
e.addSQL(getCreateSQL());
createException = e;
// if it can't be compiled, then it's a 'zero column table'
// If it can't be compiled, then it's a 'zero column table'
// this avoids problems when creating the view when opening the
// database
// if it can not be compiled - it could also be a recursive common table expression query
if(isRecursiveQueryExceptionDetected(createException)){
this.isRecursiveQueryDetected = true;
// database.
// If it can not be compiled - it could also be a recursive common table expression query.
if (isRecursiveQueryExceptionDetected(createException)) {
this.isRecursiveQueryDetected = true;
}
tables = New.arrayList();
cols = new Column[0];
......@@ -672,30 +671,28 @@ public class TableView extends Table {
return true;
}
}
/**
* If query recursion is detected (for recursion detection)
* @return is Recursive Query Flag Set
* Was query recursion detected during compiling.
*/
public boolean isRecursiveQueryDetected(){
return isRecursiveQueryDetected;
public boolean isRecursiveQueryDetected() {
return isRecursiveQueryDetected;
}
/**
* If query an exception indicates query recursion
* @return is Recursive Query Exception Detected
*/
private boolean isRecursiveQueryExceptionDetected(DbException exception){
if (exception==null){
return false;
}
if (exception.getErrorCode()!=ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1){
return false;
}
if (! exception.getMessage().contains("\""+this.getName()+"\"")){
return false;
}
return true;
* Does exception indicate query recursion?
*/
private boolean isRecursiveQueryExceptionDetected(DbException exception) {
if (exception == null) {
return false;
}
if (exception.getErrorCode() != ErrorCode.TABLE_OR_VIEW_NOT_FOUND_1) {
return false;
}
if (!exception.getMessage().contains("\"" + this.getName() + "\"")) {
return false;
}
return true;
}
}
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