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[jOOQ/jOOQ#10711] Emulate using WITH in UNION subqueries in dialects where this isn't supported

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This commit is contained in:
Lukas Eder 2020-10-05 12:17:23 +02:00
parent 640e49ac78
commit 5f56deaa3f
1 changed files with 34 additions and 12 deletions
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46
jOOQ/src/main/java/org/jooq/impl/SelectQueryImpl.java
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@ -1794,7 +1794,13 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
// [#3676] There might be cases where nested set operations do not
// imply required parentheses in some dialects, but better
// play safe than sorry
unionParenthesis(context, '(', alternativeFields != null ? alternativeFields : getSelect().toArray(EMPTY_FIELD), unionParensRequired = unionOpNesting || unionParensRequired(context));
unionParenthesis(
context,
'(',
alternativeFields != null ? alternativeFields : getSelect().toArray(EMPTY_FIELD),
derivedTableRequired(context, this),
unionParensRequired = unionOpNesting || unionParensRequired(context)
);
}
}
@ -2105,12 +2111,14 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
// SET operations like UNION, EXCEPT, INTERSECT
// --------------------------------------------
if (unionOpSize > 0) {
unionParenthesis(context, ')', null, unionParensRequired);
unionParenthesis(context, ')', null, derivedTableRequired(context, this), unionParensRequired);
for (int i = 0; i < unionOpSize; i++) {
CombineOperator op = unionOp.get(i);
for (Select<?> other : union.get(i)) {
boolean derivedTableRequired = derivedTableRequired(context, other);
context.formatSeparator()
.visit(op.toKeyword(family));
@ -2119,14 +2127,14 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
else
context.formatSeparator();
unionParenthesis(context, '(', other.getSelect().toArray(EMPTY_FIELD), unionParensRequired);
unionParenthesis(context, '(', other.getSelect().toArray(EMPTY_FIELD), derivedTableRequired, unionParensRequired);
context.visit(other);
unionParenthesis(context, ')', null, unionParensRequired);
unionParenthesis(context, ')', null, derivedTableRequired, unionParensRequired);
}
// [#1658] Close parentheses opened previously
if (i < unionOpSize - 1)
unionParenthesis(context, ')', null, unionParensRequired);
unionParenthesis(context, ')', null, derivedTableRequired(context, this), unionParensRequired);
switch (unionOp.get(i)) {
case EXCEPT: context.end(SELECT_EXCEPT); break;
@ -2689,7 +2697,8 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
private static final Set<SQLDialect> NO_SUPPORT_UNION_PARENTHESES = SQLDialect.supportedBy(SQLITE);
private static final Set<SQLDialect> UNION_PARENTHESIS = SQLDialect.supportedBy(DERBY, MARIADB, MYSQL);
private static final Set<SQLDialect> NO_SUPPORT_CTE_IN_UNION = SQLDialect.supportedBy(HSQLDB);
private static final Set<SQLDialect> UNION_PARENTHESIS = SQLDialect.supportedBy(DERBY, MARIADB, MYSQL);
final boolean hasUnions() {
return !unionOp.isEmpty();
@ -2708,6 +2717,13 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
return false;
}
private final boolean derivedTableRequired(Context<?> context, Select<?> s1) {
SelectQueryImpl<?> s;
// [#10711] Some derived tables are needed if dialects don't support CTE in union subqueries
return NO_SUPPORT_CTE_IN_UNION.contains(context.dialect()) && (s = selectQueryImpl(s1)) != null && s.with != null;
}
private final boolean unionParensRequired(Context<?> context) {
if (unionParensRequired(this) || context.settings().isRenderParenthesisAroundSetOperationQueries())
return true;
@ -2732,17 +2748,23 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
return s.orderBy.size() > 0 || s.limit.isApplicable() || s.with != null;
}
private final boolean unionParenthesis(Context<?> ctx, char parenthesis, Field<?>[] fields, boolean parensRequired) {
private final boolean unionParenthesis(
Context<?> ctx,
char parenthesis,
Field<?>[] fields,
boolean derivedTableRequired,
boolean parensRequired
) {
if ('(' == parenthesis)
ctx.subquery(true);
else if (')' == parenthesis)
ctx.subquery(false);
boolean derivedTable =
derivedTableRequired |= derivedTableRequired
// [#3579] [#6431] [#7222] Some databases don't support nested set operations at all
// because they do not allow wrapping set op subqueries in parentheses
NO_SUPPORT_UNION_PARENTHESES.contains(ctx.dialect())
|| NO_SUPPORT_UNION_PARENTHESES.contains(ctx.dialect())
// [#3579] [#6431] [#7222] Nested set operations aren't supported, but parenthesised
// set op subqueries are.
@ -2753,7 +2775,7 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
|| TRUE.equals(ctx.data(DATA_INSERT_SELECT_WITHOUT_INSERT_COLUMN_LIST))
;
parensRequired |= derivedTable;
parensRequired |= derivedTableRequired;
if (parensRequired && ')' == parenthesis) {
ctx.formatIndentEnd()
@ -2763,7 +2785,7 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
// [#3579] Nested set operators aren't supported in some databases. Emulate them via derived tables...
// [#7222] Do this only in the presence of actual nested set operators
else if (parensRequired && '(' == parenthesis) {
if (derivedTable) {
if (derivedTableRequired) {
ctx.formatNewLine()
.visit(K_SELECT).sql(' ');
@ -2803,7 +2825,7 @@ final class SelectQueryImpl<R extends Record> extends AbstractResultQuery<R> imp
}
else if (parensRequired && ')' == parenthesis) {
if (derivedTable)
if (derivedTableRequired)
ctx.sql(" x");
}