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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.calcite.sql;

import org.apache.calcite.linq4j.Ord;
import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.rex.RexWindowBound;
import org.apache.calcite.sql.parser.SqlParserPos;
import org.apache.calcite.sql.type.ReturnTypes;
import org.apache.calcite.sql.type.SqlTypeFamily;
import org.apache.calcite.sql.util.SqlBasicVisitor;
import org.apache.calcite.sql.util.SqlVisitor;
import org.apache.calcite.sql.validate.SqlValidator;
import org.apache.calcite.sql.validate.SqlValidatorScope;
import org.apache.calcite.sql.validate.SqlValidatorUtil;
import org.apache.calcite.util.ControlFlowException;
import org.apache.calcite.util.ImmutableNullableList;
import org.apache.calcite.util.Litmus;
import org.apache.calcite.util.Util;

import com.google.common.collect.ImmutableList;

import java.util.List;

import static org.apache.calcite.util.Static.RESOURCE;

/**
 * SQL window specification.
 *
 * 

For example, the query

* *
*
SELECT sum(a) OVER (w ROWS 3 PRECEDING)
 * FROM t
 * WINDOW w AS (PARTITION BY x, y ORDER BY z),
 *     w1 AS (w ROWS 5 PRECEDING UNBOUNDED FOLLOWING)
*
* *

declares windows w and w1, and uses a window in an OVER clause. It thus * contains 3 {@link SqlWindow} objects.

*/ public class SqlWindow extends SqlCall { /** * The FOLLOWING operator used exclusively in a window specification. */ static final SqlPostfixOperator FOLLOWING_OPERATOR = new SqlPostfixOperator("FOLLOWING", SqlKind.FOLLOWING, 20, ReturnTypes.ARG0, null, null); /** * The PRECEDING operator used exclusively in a window specification. */ static final SqlPostfixOperator PRECEDING_OPERATOR = new SqlPostfixOperator("PRECEDING", SqlKind.PRECEDING, 20, ReturnTypes.ARG0, null, null); //~ Instance fields -------------------------------------------------------- /** The name of the window being declared. */ SqlIdentifier declName; /** The name of the window being referenced, or null. */ SqlIdentifier refName; /** The list of partitioning columns. */ SqlNodeList partitionList; /** The list of ordering columns. */ SqlNodeList orderList; /** Whether it is a physical (rows) or logical (values) range. */ SqlLiteral isRows; /** The lower bound of the window. */ SqlNode lowerBound; /** The upper bound of the window. */ SqlNode upperBound; /** Whether to allow partial results. It may be null. */ SqlLiteral allowPartial; private SqlCall windowCall = null; //~ Constructors ----------------------------------------------------------- /** * Creates a window. */ public SqlWindow(SqlParserPos pos, SqlIdentifier declName, SqlIdentifier refName, SqlNodeList partitionList, SqlNodeList orderList, SqlLiteral isRows, SqlNode lowerBound, SqlNode upperBound, SqlLiteral allowPartial) { super(pos); this.declName = declName; this.refName = refName; this.partitionList = partitionList; this.orderList = orderList; this.isRows = isRows; this.lowerBound = lowerBound; this.upperBound = upperBound; this.allowPartial = allowPartial; assert declName == null || declName.isSimple(); assert partitionList != null; assert orderList != null; } public static SqlWindow create(SqlIdentifier declName, SqlIdentifier refName, SqlNodeList partitionList, SqlNodeList orderList, SqlLiteral isRows, SqlNode lowerBound, SqlNode upperBound, SqlLiteral allowPartial, SqlParserPos pos) { // If there's only one bound and it's 'FOLLOWING', make it the upper // bound. if (upperBound == null && lowerBound != null && lowerBound.getKind() == SqlKind.FOLLOWING) { upperBound = lowerBound; lowerBound = null; } return new SqlWindow(pos, declName, refName, partitionList, orderList, isRows, lowerBound, upperBound, allowPartial); } //~ Methods ---------------------------------------------------------------- public SqlOperator getOperator() { return SqlWindowOperator.INSTANCE; } @Override public SqlKind getKind() { return SqlKind.WINDOW; } public List getOperandList() { return ImmutableNullableList.of(declName, refName, partitionList, orderList, isRows, lowerBound, upperBound, allowPartial); } @Override public void setOperand(int i, SqlNode operand) { switch (i) { case 0: this.declName = (SqlIdentifier) operand; break; case 1: this.refName = (SqlIdentifier) operand; break; case 2: this.partitionList = (SqlNodeList) operand; break; case 3: this.orderList = (SqlNodeList) operand; break; case 4: this.isRows = (SqlLiteral) operand; break; case 5: this.lowerBound = operand; break; case 6: this.upperBound = operand; break; case 7: this.allowPartial = (SqlLiteral) operand; break; default: throw new AssertionError(i); } } @Override public void unparse(SqlWriter writer, int leftPrec, int rightPrec) { if (null != declName) { declName.unparse(writer, 0, 0); writer.keyword("AS"); } // Override, so we don't print extra parentheses. getOperator().unparse(writer, this, 0, 0); } public SqlIdentifier getDeclName() { return declName; } public void setDeclName(SqlIdentifier declName) { assert declName.isSimple(); this.declName = declName; } public SqlNode getLowerBound() { return lowerBound; } public void setLowerBound(SqlNode lowerBound) { this.lowerBound = lowerBound; } public SqlNode getUpperBound() { return upperBound; } public void setUpperBound(SqlNode upperBound) { this.upperBound = upperBound; } /** * Returns if the window is guaranteed to have rows. * This is useful to refine data type of window aggregates. * For instance sum(non-nullable) over (empty window) is NULL. * * @return true when the window is non-empty * * @see org.apache.calcite.rel.core.Window.Group#isAlwaysNonEmpty() * @see SqlOperatorBinding#getGroupCount() * @see org.apache.calcite.sql.validate.SqlValidatorImpl#resolveWindow(SqlNode, org.apache.calcite.sql.validate.SqlValidatorScope, boolean) */ public boolean isAlwaysNonEmpty() { final SqlWindow tmp; if (lowerBound == null || upperBound == null) { // Keep the current window unmodified tmp = new SqlWindow(getParserPosition(), null, null, partitionList, orderList, isRows, lowerBound, upperBound, allowPartial); tmp.populateBounds(); } else { tmp = this; } if (tmp.lowerBound instanceof SqlLiteral && tmp.upperBound instanceof SqlLiteral) { int lowerKey = RexWindowBound.create(tmp.lowerBound, null).getOrderKey(); int upperKey = RexWindowBound.create(tmp.upperBound, null).getOrderKey(); return lowerKey > -1 && lowerKey <= upperKey; } return false; } public void setRows(SqlLiteral isRows) { this.isRows = isRows; } public boolean isRows() { return isRows.booleanValue(); } public SqlNodeList getOrderList() { return orderList; } public void setOrderList(SqlNodeList orderList) { this.orderList = orderList; } public SqlNodeList getPartitionList() { return partitionList; } public void setPartitionList(SqlNodeList partitionList) { this.partitionList = partitionList; } public SqlIdentifier getRefName() { return refName; } public void setWindowCall(SqlCall windowCall) { this.windowCall = windowCall; assert windowCall == null || windowCall.getOperator() instanceof SqlAggFunction; } public SqlCall getWindowCall() { return windowCall; } /** @see Util#deprecated(Object, boolean) */ static void checkSpecialLiterals(SqlWindow window, SqlValidator validator) { final SqlNode lowerBound = window.getLowerBound(); final SqlNode upperBound = window.getUpperBound(); Object lowerLitType = null; Object upperLitType = null; SqlOperator lowerOp = null; SqlOperator upperOp = null; if (null != lowerBound) { if (lowerBound.getKind() == SqlKind.LITERAL) { lowerLitType = ((SqlLiteral) lowerBound).getValue(); if (Bound.UNBOUNDED_FOLLOWING == lowerLitType) { throw validator.newValidationError(lowerBound, RESOURCE.badLowerBoundary()); } } else if (lowerBound instanceof SqlCall) { lowerOp = ((SqlCall) lowerBound).getOperator(); } } if (null != upperBound) { if (upperBound.getKind() == SqlKind.LITERAL) { upperLitType = ((SqlLiteral) upperBound).getValue(); if (Bound.UNBOUNDED_PRECEDING == upperLitType) { throw validator.newValidationError(upperBound, RESOURCE.badUpperBoundary()); } } else if (upperBound instanceof SqlCall) { upperOp = ((SqlCall) upperBound).getOperator(); } } if (Bound.CURRENT_ROW == lowerLitType) { if (null != upperOp) { if (upperOp == PRECEDING_OPERATOR) { throw validator.newValidationError(upperBound, RESOURCE.currentRowPrecedingError()); } } } else if (null != lowerOp) { if (lowerOp == FOLLOWING_OPERATOR) { if (null != upperOp) { if (upperOp == PRECEDING_OPERATOR) { throw validator.newValidationError(upperBound, RESOURCE.followingBeforePrecedingError()); } } else if (null != upperLitType) { if (Bound.CURRENT_ROW == upperLitType) { throw validator.newValidationError(upperBound, RESOURCE.currentRowFollowingError()); } } } } } public static SqlNode createCurrentRow(SqlParserPos pos) { return Bound.CURRENT_ROW.symbol(pos); } public static SqlNode createUnboundedFollowing(SqlParserPos pos) { return Bound.UNBOUNDED_FOLLOWING.symbol(pos); } public static SqlNode createUnboundedPreceding(SqlParserPos pos) { return Bound.UNBOUNDED_PRECEDING.symbol(pos); } public static SqlNode createFollowing(SqlNode e, SqlParserPos pos) { return FOLLOWING_OPERATOR.createCall(pos, e); } public static SqlNode createPreceding(SqlNode e, SqlParserPos pos) { return PRECEDING_OPERATOR.createCall(pos, e); } public static SqlNode createBound(SqlLiteral range) { return range; } /** * Returns whether an expression represents the "CURRENT ROW" bound. */ public static boolean isCurrentRow(SqlNode node) { return (node instanceof SqlLiteral) && ((SqlLiteral) node).symbolValue(Bound.class) == Bound.CURRENT_ROW; } /** * Returns whether an expression represents the "UNBOUNDED PRECEDING" bound. */ public static boolean isUnboundedPreceding(SqlNode node) { return (node instanceof SqlLiteral) && ((SqlLiteral) node).symbolValue(Bound.class) == Bound.UNBOUNDED_PRECEDING; } /** * Returns whether an expression represents the "UNBOUNDED FOLLOWING" bound. */ public static boolean isUnboundedFollowing(SqlNode node) { return (node instanceof SqlLiteral) && ((SqlLiteral) node).symbolValue(Bound.class) == Bound.UNBOUNDED_FOLLOWING; } /** * Creates a new window by combining this one with another. * *

For example, * *

WINDOW (w PARTITION BY x ORDER BY y)
   *   overlay
   *   WINDOW w AS (PARTITION BY z)
* *

yields * *

WINDOW (PARTITION BY z ORDER BY y)
* *

Does not alter this or the other window. * * @return A new window */ public SqlWindow overlay(SqlWindow that, SqlValidator validator) { // check 7.11 rule 10c final SqlNodeList partitions = getPartitionList(); if (0 != partitions.size()) { throw validator.newValidationError(partitions.get(0), RESOURCE.partitionNotAllowed()); } // 7.11 rule 10d final SqlNodeList baseOrder = getOrderList(); final SqlNodeList refOrder = that.getOrderList(); if ((0 != baseOrder.size()) && (0 != refOrder.size())) { throw validator.newValidationError(baseOrder.get(0), RESOURCE.orderByOverlap()); } // 711 rule 10e final SqlNode lowerBound = that.getLowerBound(); final SqlNode upperBound = that.getUpperBound(); if ((null != lowerBound) || (null != upperBound)) { throw validator.newValidationError(that.isRows, RESOURCE.refWindowWithFrame()); } SqlIdentifier declNameNew = declName; SqlIdentifier refNameNew = refName; SqlNodeList partitionListNew = partitionList; SqlNodeList orderListNew = orderList; SqlLiteral isRowsNew = isRows; SqlNode lowerBoundNew = lowerBound; SqlNode upperBoundNew = upperBound; SqlLiteral allowPartialNew = allowPartial; // Clear the reference window, because the reference is now resolved. // The overlaying window may have its own reference, of course. refNameNew = null; // Overlay other parameters. if (setOperand(partitionListNew, that.partitionList, validator)) { partitionListNew = that.partitionList; } if (setOperand(orderListNew, that.orderList, validator)) { orderListNew = that.orderList; } if (setOperand(lowerBoundNew, that.lowerBound, validator)) { lowerBoundNew = that.lowerBound; } if (setOperand(upperBoundNew, that.upperBound, validator)) { upperBoundNew = that.upperBound; } return new SqlWindow( SqlParserPos.ZERO, declNameNew, refNameNew, partitionListNew, orderListNew, isRowsNew, lowerBoundNew, upperBoundNew, allowPartialNew); } private static boolean setOperand(SqlNode clonedOperand, SqlNode thatOperand, SqlValidator validator) { if ((thatOperand != null) && !SqlNodeList.isEmptyList(thatOperand)) { if ((clonedOperand == null) || SqlNodeList.isEmptyList(clonedOperand)) { return true; } else { throw validator.newValidationError(clonedOperand, RESOURCE.cannotOverrideWindowAttribute()); } } return false; } /** * Overridden method to specifically check only the right subtree of a window * definition. * * @param node The SqlWindow to compare to "this" window * @param litmus What to do if an error is detected (nodes are not equal) * * @return boolean true if all nodes in the subtree are equal */ @Override public boolean equalsDeep(SqlNode node, Litmus litmus) { // This is the difference over super.equalsDeep. It skips // operands[0] the declared name fo this window. We only want // to check the window components. return node == this || node instanceof SqlWindow && SqlNode.equalDeep( Util.skip(getOperandList()), Util.skip(((SqlWindow) node).getOperandList()), litmus); } /** * Returns whether partial windows are allowed. If false, a partial window * (for example, a window of size 1 hour which has only 45 minutes of data * in it) will appear to windowed aggregate functions to be empty. */ public boolean isAllowPartial() { // Default (and standard behavior) is to allow partial windows. return allowPartial == null || allowPartial.booleanValue(); } @Override public void validate(SqlValidator validator, SqlValidatorScope scope) { SqlValidatorScope operandScope = scope; // REVIEW SqlIdentifier declName = this.declName; SqlIdentifier refName = this.refName; SqlNodeList partitionList = this.partitionList; SqlNodeList orderList = this.orderList; SqlLiteral isRows = this.isRows; SqlNode lowerBound = this.lowerBound; SqlNode upperBound = this.upperBound; SqlLiteral allowPartial = this.allowPartial; if (refName != null) { SqlWindow win = validator.resolveWindow(this, operandScope, false); partitionList = win.partitionList; orderList = win.orderList; isRows = win.isRows; lowerBound = win.lowerBound; upperBound = win.upperBound; allowPartial = win.allowPartial; } for (SqlNode partitionItem : partitionList) { try { partitionItem.accept(Util.OverFinder.INSTANCE); } catch (ControlFlowException e) { throw validator.newValidationError(this, RESOURCE.partitionbyShouldNotContainOver()); } partitionItem.validateExpr(validator, operandScope); } for (SqlNode orderItem : orderList) { boolean savedColumnReferenceExpansion = validator.getColumnReferenceExpansion(); validator.setColumnReferenceExpansion(false); try { orderItem.accept(Util.OverFinder.INSTANCE); } catch (ControlFlowException e) { throw validator.newValidationError(this, RESOURCE.orderbyShouldNotContainOver()); } try { orderItem.validateExpr(validator, scope); } finally { validator.setColumnReferenceExpansion( savedColumnReferenceExpansion); } } // 6.10 rule 6a Function RANK & DENSE_RANK require ORDER BY clause if (orderList.size() == 0 && !SqlValidatorUtil.containsMonotonic(scope) && windowCall != null && windowCall.getOperator().requiresOrder()) { throw validator.newValidationError(this, RESOURCE.funcNeedsOrderBy()); } // Run framing checks if there are any if (upperBound != null || lowerBound != null) { // 6.10 Rule 6a RANK & DENSE_RANK do not allow ROWS or RANGE if (windowCall != null && !windowCall.getOperator().allowsFraming()) { throw validator.newValidationError(isRows, RESOURCE.rankWithFrame()); } SqlTypeFamily orderTypeFam = null; // SQL03 7.10 Rule 11a if (orderList.size() > 0) { // if order by is a compound list then range not allowed if (orderList.size() > 1 && !isRows()) { throw validator.newValidationError(isRows, RESOURCE.compoundOrderByProhibitsRange()); } // get the type family for the sort key for Frame Boundary Val. RelDataType orderType = validator.deriveType( operandScope, orderList.get(0)); orderTypeFam = orderType.getSqlTypeName().getFamily(); } else { // requires an ORDER BY clause if frame is logical(RANGE) // We relax this requirement if the table appears to be // sorted already if (!isRows() && !SqlValidatorUtil.containsMonotonic(scope)) { throw validator.newValidationError(this, RESOURCE.overMissingOrderBy()); } } // Let the bounds validate themselves validateFrameBoundary( lowerBound, isRows(), orderTypeFam, validator, operandScope); validateFrameBoundary( upperBound, isRows(), orderTypeFam, validator, operandScope); // Validate across boundaries. 7.10 Rule 8 a-d checkSpecialLiterals(this, validator); } else if (orderList.size() == 0 && !SqlValidatorUtil.containsMonotonic(scope) && windowCall != null && windowCall.getOperator().requiresOrder()) { throw validator.newValidationError(this, RESOURCE.overMissingOrderBy()); } if (!isRows() && !isAllowPartial()) { throw validator.newValidationError(allowPartial, RESOURCE.cannotUseDisallowPartialWithRange()); } } private void validateFrameBoundary( SqlNode bound, boolean isRows, SqlTypeFamily orderTypeFam, SqlValidator validator, SqlValidatorScope scope) { if (null == bound) { return; } bound.validate(validator, scope); switch (bound.getKind()) { case LITERAL: // is there really anything to validate here? this covers // "CURRENT_ROW","unbounded preceding" & "unbounded following" break; case OTHER: case FOLLOWING: case PRECEDING: assert bound instanceof SqlCall; final SqlNode boundVal = ((SqlCall) bound).operand(0); // SQL03 7.10 rule 11b Physical ROWS must be a numeric constant. JR: // actually it's SQL03 7.11 rule 11b "exact numeric with scale 0" // means not only numeric constant but exact numeric integral // constant. We also interpret the spec. to not allow negative // values, but allow zero. if (isRows) { if (boundVal instanceof SqlNumericLiteral) { final SqlNumericLiteral boundLiteral = (SqlNumericLiteral) boundVal; if ((!boundLiteral.isExact()) || (boundLiteral.getScale() != 0) || (0 > boundLiteral.longValue(true))) { // true == throw if not exact (we just tested that - right?) throw validator.newValidationError(boundVal, RESOURCE.rowMustBeNonNegativeIntegral()); } } else { // Allow expressions in ROWS clause } } // if this is a range spec check and make sure the boundary type // and order by type are compatible if (orderTypeFam != null && !isRows) { RelDataType bndType = validator.deriveType(scope, boundVal); SqlTypeFamily bndTypeFam = bndType.getSqlTypeName().getFamily(); switch (orderTypeFam) { case NUMERIC: if (SqlTypeFamily.NUMERIC != bndTypeFam) { throw validator.newValidationError(boundVal, RESOURCE.orderByRangeMismatch()); } break; case DATE: case TIME: case TIMESTAMP: if (SqlTypeFamily.INTERVAL_DAY_TIME != bndTypeFam && SqlTypeFamily.INTERVAL_YEAR_MONTH != bndTypeFam) { throw validator.newValidationError(boundVal, RESOURCE.orderByRangeMismatch()); } break; default: throw validator.newValidationError(boundVal, RESOURCE.orderByDataTypeProhibitsRange()); } } break; default: throw new AssertionError("Unexpected node type"); } } /** * Creates a window (RANGE columnName CURRENT ROW). * * @param columnName Order column */ public SqlWindow createCurrentRowWindow(final String columnName) { return SqlWindow.create( null, null, new SqlNodeList(SqlParserPos.ZERO), new SqlNodeList( ImmutableList.of( new SqlIdentifier(columnName, SqlParserPos.ZERO)), SqlParserPos.ZERO), SqlLiteral.createBoolean(true, SqlParserPos.ZERO), SqlWindow.createCurrentRow(SqlParserPos.ZERO), SqlWindow.createCurrentRow(SqlParserPos.ZERO), SqlLiteral.createBoolean(true, SqlParserPos.ZERO), SqlParserPos.ZERO); } /** * Creates a window (RANGE columnName UNBOUNDED * PRECEDING). * * @param columnName Order column */ public SqlWindow createUnboundedPrecedingWindow(final String columnName) { return SqlWindow.create( null, null, new SqlNodeList(SqlParserPos.ZERO), new SqlNodeList( ImmutableList.of( new SqlIdentifier(columnName, SqlParserPos.ZERO)), SqlParserPos.ZERO), SqlLiteral.createBoolean(false, SqlParserPos.ZERO), SqlWindow.createUnboundedPreceding(SqlParserPos.ZERO), SqlWindow.createCurrentRow(SqlParserPos.ZERO), SqlLiteral.createBoolean(false, SqlParserPos.ZERO), SqlParserPos.ZERO); } /** * Fill in missing bounds. Default bounds are "BETWEEN UNBOUNDED PRECEDING * AND CURRENT ROW" when ORDER BY present and "BETWEEN UNBOUNDED PRECEDING * AND UNBOUNDED FOLLOWING" when no ORDER BY present. */ public void populateBounds() { if (lowerBound == null && upperBound == null) { setLowerBound( SqlWindow.createUnboundedPreceding(getParserPosition())); } if (lowerBound == null) { setLowerBound( SqlWindow.createCurrentRow(getParserPosition())); } if (upperBound == null) { SqlParserPos pos = orderList.getParserPosition(); setUpperBound( orderList.size() == 0 ? SqlWindow.createUnboundedFollowing(pos) : SqlWindow.createCurrentRow(pos)); } } /** * An enumeration of types of bounds in a window: CURRENT ROW, * UNBOUNDED PRECEDING, and UNBOUNDED FOLLOWING. */ enum Bound { CURRENT_ROW("CURRENT ROW"), UNBOUNDED_PRECEDING("UNBOUNDED PRECEDING"), UNBOUNDED_FOLLOWING("UNBOUNDED FOLLOWING"); private final String sql; Bound(String sql) { this.sql = sql; } public String toString() { return sql; } /** * Creates a parse-tree node representing an occurrence of this bound * type at a particular position in the parsed text. */ public SqlNode symbol(SqlParserPos pos) { return SqlLiteral.createSymbol(this, pos); } } /** An operator describing a window specification. */ private static class SqlWindowOperator extends SqlOperator { private static final SqlWindowOperator INSTANCE = new SqlWindowOperator(); private SqlWindowOperator() { super("WINDOW", SqlKind.WINDOW, 2, true, null, null, null); } public SqlSyntax getSyntax() { return SqlSyntax.SPECIAL; } public SqlCall createCall( SqlLiteral functionQualifier, SqlParserPos pos, SqlNode... operands) { assert functionQualifier == null; assert operands.length == 8; return create( (SqlIdentifier) operands[0], (SqlIdentifier) operands[1], (SqlNodeList) operands[2], (SqlNodeList) operands[3], (SqlLiteral) operands[4], operands[5], operands[6], (SqlLiteral) operands[7], pos); } public void acceptCall( SqlVisitor visitor, SqlCall call, boolean onlyExpressions, SqlBasicVisitor.ArgHandler argHandler) { if (onlyExpressions) { for (Ord operand : Ord.zip(call.getOperandList())) { // if the second param is an Identifier then it's supposed to // be a name from a window clause and isn't part of the // group by check if (operand.e == null) { continue; } if (operand.i == 1 && operand.e instanceof SqlIdentifier) { // skip refName continue; } argHandler.visitChild(visitor, call, operand.i, operand.e); } } else { super.acceptCall(visitor, call, onlyExpressions, argHandler); } } public void unparse( SqlWriter writer, SqlCall call, int leftPrec, int rightPrec) { final SqlWindow window = (SqlWindow) call; final SqlWriter.Frame frame = writer.startList(SqlWriter.FrameTypeEnum.WINDOW, "(", ")"); if (window.refName != null) { window.refName.unparse(writer, 0, 0); } if (window.partitionList.size() > 0) { writer.sep("PARTITION BY"); final SqlWriter.Frame partitionFrame = writer.startList("", ""); window.partitionList.unparse(writer, 0, 0); writer.endList(partitionFrame); } if (window.orderList.size() > 0) { writer.sep("ORDER BY"); final SqlWriter.Frame orderFrame = writer.startList("", ""); window.orderList.unparse(writer, 0, 0); writer.endList(orderFrame); } if (window.lowerBound == null) { // No ROWS or RANGE clause } else if (window.upperBound == null) { if (window.isRows()) { writer.sep("ROWS"); } else { writer.sep("RANGE"); } window.lowerBound.unparse(writer, 0, 0); } else { if (window.isRows()) { writer.sep("ROWS BETWEEN"); } else { writer.sep("RANGE BETWEEN"); } window.lowerBound.unparse(writer, 0, 0); writer.keyword("AND"); window.upperBound.unparse(writer, 0, 0); } // ALLOW PARTIAL/DISALLOW PARTIAL if (window.allowPartial == null) { // do nothing } else if (window.isAllowPartial()) { // We could output "ALLOW PARTIAL", but this syntax is // non-standard. Omitting the clause has the same effect. } else { writer.keyword("DISALLOW PARTIAL"); } writer.endList(frame); } } } // End SqlWindow.java





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