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提交 21036320 authored 作者: Evgenij Ryazanov's avatar Evgenij Ryazanov
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Add UNNEST table function

上级 f33de19b
隐藏空白字符变更
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正在显示 包含 117 行增加 和 34 行删除
h2/src/docsrc/help/help.csv
浏览文件 @ 21036320
......@@ -5215,6 +5215,18 @@ The method returns a value with the same data type as the first parameter.
CALL TRUNCATE_VALUE(X, 10, TRUE);
"
"Functions (System)","UNNEST","
UNNEST(array, [,...]) [WITH ORDINALITY]
","
Returns the result set.
Number of columns is equal to number of arguments,
plus one additional column with row number if WITH ORDINALITY is specified.
Number of rows is equal to length of longest specified array.
If multiple arguments are specified and they have different length, cells with missing values will contain null values.
","
SELECT * FROM UNNEST(ARRAY['a', 'b', 'c']);
"
"Functions (System)","USER","
{ USER | CURRENT_USER } ()
","
......
h2/src/main/org/h2/command/Parser.java
浏览文件 @ 21036320
......@@ -3406,6 +3406,23 @@ public class Parser {
tf.setColumns(columns);
break;
}
case Function.UNNEST: {
ArrayList<Column> columns = Utils.newSmallArrayList();
if (!readIf(CLOSE_PAREN)) {
int i = 0;
do {
function.setParameter(i++, readExpression());
columns.add(new Column("C" + i, Value.NULL));
} while (readIfMore(true));
}
if (readIf(WITH)) {
read("ORDINALITY");
columns.add(new Column("NORD", Value.INT));
}
TableFunction tf = (TableFunction) function;
tf.setColumns(columns);
break;
}
default:
if (!readIf(CLOSE_PAREN)) {
int i = 0;
......
h2/src/main/org/h2/expression/function/Function.java
浏览文件 @ 21036320
......@@ -134,7 +134,8 @@ public class Function extends Expression implements FunctionCall {
ARRAY_LENGTH = 217, LINK_SCHEMA = 218, GREATEST = 219, LEAST = 220,
CANCEL_SESSION = 221, SET = 222, TABLE = 223, TABLE_DISTINCT = 224,
FILE_READ = 225, TRANSACTION_ID = 226, TRUNCATE_VALUE = 227,
NVL2 = 228, DECODE = 229, ARRAY_CONTAINS = 230, FILE_WRITE = 232;
NVL2 = 228, DECODE = 229, ARRAY_CONTAINS = 230, FILE_WRITE = 232,
UNNEST = 233;
public static final int REGEXP_LIKE = 240;
......@@ -459,10 +460,9 @@ public class Function extends Expression implements FunctionCall {
addFunction("H2VERSION", H2VERSION, 0, Value.STRING);
// TableFunction
addFunctionWithNull("TABLE", TABLE,
VAR_ARGS, Value.RESULT_SET);
addFunctionWithNull("TABLE_DISTINCT", TABLE_DISTINCT,
VAR_ARGS, Value.RESULT_SET);
addFunctionWithNull("TABLE", TABLE, VAR_ARGS, Value.RESULT_SET);
addFunctionWithNull("TABLE_DISTINCT", TABLE_DISTINCT, VAR_ARGS, Value.RESULT_SET);
addFunctionWithNull("UNNEST", UNNEST, VAR_ARGS, Value.RESULT_SET);
// ON DUPLICATE KEY VALUES function
addFunction("VALUES", VALUES, 1, Value.NULL, false, true, false, true);
......@@ -538,6 +538,7 @@ public class Function extends Expression implements FunctionCall {
switch (info.type) {
case TABLE:
case TABLE_DISTINCT:
case UNNEST:
return new TableFunction(database, info, Long.MAX_VALUE);
default:
return new Function(database, info);
......
h2/src/main/org/h2/expression/function/TableFunction.java
浏览文件 @ 21036320
......@@ -17,6 +17,7 @@ import org.h2.result.LocalResult;
import org.h2.table.Column;
import org.h2.value.Value;
import org.h2.value.ValueArray;
import org.h2.value.ValueInt;
import org.h2.value.ValueNull;
import org.h2.value.ValueResultSet;
......@@ -24,19 +25,17 @@ import org.h2.value.ValueResultSet;
* Implementation of the functions TABLE(..) and TABLE_DISTINCT(..).
*/
public class TableFunction extends Function {
private final boolean distinct;
private final long rowCount;
private Column[] columnList;
private Column[] columns;
TableFunction(Database database, FunctionInfo info, long rowCount) {
super(database, info);
distinct = info.type == Function.TABLE_DISTINCT;
this.rowCount = rowCount;
}
@Override
public Value getValue(Session session) {
return getTable(session, args, false, distinct);
return getTable(session, false);
}
@Override
......@@ -48,52 +47,60 @@ public class TableFunction extends Function {
@Override
public StringBuilder getSQL(StringBuilder builder) {
if (info.type == UNNEST) {
super.getSQL(builder);
if (args.length < columns.length) {
builder.append(" WITH ORDINALITY");
}
return builder;
}
builder.append(getName()).append('(');
for (int i = 0; i < args.length; i++) {
if (i > 0) {
builder.append(", ");
}
builder.append(columnList[i].getCreateSQL()).append('=');
builder.append(columns[i].getCreateSQL()).append('=');
args[i].getSQL(builder);
}
return builder.append(')');
}
@Override
public String getName() {
return distinct ? "TABLE_DISTINCT" : "TABLE";
}
@Override
public ValueResultSet getValueForColumnList(Session session,
Expression[] nullArgs) {
return getTable(session, args, true, false);
return getTable(session, true);
}
public void setColumns(ArrayList<Column> columns) {
this.columnList = columns.toArray(new Column[0]);
this.columns = columns.toArray(new Column[0]);
}
private ValueResultSet getTable(Session session, Expression[] argList,
boolean onlyColumnList, boolean distinctRows) {
int len = columnList.length;
Expression[] header = new Expression[len];
private ValueResultSet getTable(Session session, boolean onlyColumnList) {
int totalColumns = columns.length;
Expression[] header = new Expression[totalColumns];
Database db = session.getDatabase();
for (int i = 0; i < len; i++) {
Column c = columnList[i];
for (int i = 0; i < totalColumns; i++) {
Column c = columns[i];
ExpressionColumn col = new ExpressionColumn(db, c);
header[i] = col;
}
LocalResult result = db.getResultFactory().create(session, header, len);
if (distinctRows) {
LocalResult result = db.getResultFactory().create(session, header, totalColumns);
if (!onlyColumnList && info.type == TABLE_DISTINCT) {
result.setDistinct();
}
if (!onlyColumnList) {
int len = totalColumns;
boolean unnest = info.type == UNNEST, addNumber = false;
if (unnest) {
len = args.length;
if (len < totalColumns) {
addNumber = true;
}
}
Value[][] list = new Value[len][];
int rows = 0;
for (int i = 0; i < len; i++) {
Value v = argList[i].getValue(session);
Value v = args[i].getValue(session);
if (v == ValueNull.INSTANCE) {
list[i] = new Value[0];
} else {
......@@ -104,21 +111,25 @@ public class TableFunction extends Function {
}
}
for (int row = 0; row < rows; row++) {
Value[] r = new Value[len];
Value[] r = new Value[totalColumns];
for (int j = 0; j < len; j++) {
Value[] l = list[j];
Value v;
if (l.length <= row) {
v = ValueNull.INSTANCE;
} else {
Column c = columnList[j];
Column c = columns[j];
v = l[row];
v = c.convert(v);
v = v.convertPrecision(c.getPrecision(), false);
v = v.convertScale(true, c.getScale());
if (!unnest) {
v = c.convert(v).convertPrecision(c.getPrecision(), false)
.convertScale(true, c.getScale());
}
}
r[j] = v;
}
if (addNumber) {
r[len] = ValueInt.get(row + 1);
}
result.addRow(r);
}
}
......@@ -132,7 +143,7 @@ public class TableFunction extends Function {
@Override
public Expression[] getExpressionColumns(Session session) {
return getExpressionColumns(session, getTable(session, getArgs(), true, false).getResult());
return getExpressionColumns(session, getValueForColumnList(session, null).getResult());
}
}
h2/src/test/org/h2/test/scripts/TestScript.java
浏览文件 @ 21036320
......@@ -194,7 +194,7 @@ public class TestScript extends TestDb {
"ifnull", "least", "link-schema", "lock-mode", "lock-timeout",
"memory-free", "memory-used", "nextval", "nullif", "nvl2",
"readonly", "rownum", "schema", "scope-identity", "session-id",
"set", "table", "transaction-id", "truncate-value", "user" }) {
"set", "table", "transaction-id", "truncate-value", "unnest", "user" }) {
testScript("functions/system/" + s + ".sql");
}
for (String s : new String[] { "add_months", "current_date", "current_timestamp",
......
h2/src/test/org/h2/test/scripts/functions/system/unnest.sql 0 → 100644
浏览文件 @ 21036320
-- Copyright 2004-2018 H2 Group. Multiple-Licensed under the MPL 2.0,
-- and the EPL 1.0 (http://h2database.com/html/license.html).
-- Initial Developer: H2 Group
--
SELECT * FROM UNNEST();
> exception INVALID_PARAMETER_COUNT_2
SELECT * FROM UNNEST(ARRAY[]);
> C1
> --
> rows: 0
SELECT * FROM UNNEST(ARRAY[1, 2, 3]);
> C1
> --
> 1
> 2
> 3
> rows: 3
SELECT * FROM UNNEST(ARRAY[1], ARRAY[2, 3, 4], ARRAY[5, 6]);
> C1 C2 C3
> ---- -- ----
> 1 2 5
> null 3 6
> null 4 null
> rows: 3
SELECT * FROM UNNEST(ARRAY[1], ARRAY[2, 3, 4], ARRAY[5, 6]) WITH ORDINALITY;
> C1 C2 C3 NORD
> ---- -- ---- ----
> 1 2 5 1
> null 3 6 2
> null 4 null 3
> rows: 3
EXPLAIN SELECT * FROM UNNEST(ARRAY[1]);
>> SELECT UNNEST.C1 FROM UNNEST((1,)) /* function */
EXPLAIN SELECT * FROM UNNEST(ARRAY[1]) WITH ORDINALITY;
>> SELECT UNNEST.C1, UNNEST.NORD FROM UNNEST((1,)) WITH ORDINALITY /* function */
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