Package org.apache.juneau.beanquery.sql

Class SqlSearchCompiler

java.lang.Object

org.apache.juneau.beanquery.sql.SqlSearchCompiler

public final class SqlSearchCompiler
extends Object

Compiles a resolved Filter tree into a SQL WHERE predicate for a SqlDialect.

This is the dialect-agnostic core of the shared JDBC engine. The terms are already parsed, allow-listed and type-checked. The compiler walks each tree and:

• combines the terms (one per column) with AND;
• combines a column's $and/$or/$not sub-expressions itself;
• delegates every leaf to the SqlDialect (a built-in via SqlDialect.builtinRenderer(String), a bare pattern via SqlDialect.renderBare(java.lang.String, org.apache.juneau.commons.beanquery.SearchType, java.lang.Object, boolean)) or, for a custom operator, to that operator's SearchSqlRenderer extension.
• a compile(Filter) caller gets the same per-leaf rendering across a resolved, cross-column tree.

The SQL result must match the in-memory result, so a built-in the dialect cannot faithfully express is rejected with a BeanQuerySyntaxException whose code is BAD_VALUE rather than rendered differently: an operator for which SqlDialect.builtinRenderer(String) returns null (for example $regex on a database without regex support), and a range/ordering operator ($gt, $gte, $lt, $lte, $between) on a VERSION column when SqlDialect.supportsVersionOrdering() is false. Equality on versions is unaffected. A custom operator with no usable renderer still raises IllegalStateException.

Example:

ResolvedQuery q = context.resolve(BeanQuery.create().gt("age", 21).eq("name", "Bob").build()); SqlFragment where = SqlSearchCompiler.create(dialect, context).compile(q.filter()); // where.sql(): "age" > ? AND "name" = ? // where.binds(): [21, Bob]

Since:

10.0.0

Method Summary

Modifier and Type	Method	Description
SqlFragment	compile(Filter filter)	Compiles an already-resolved Filter tree into a boolean WHERE predicate.
static SqlSearchCompiler	create(SqlDialect dialect, ColumnResolver columns)	Creates a compiler for a dialect and column resolver.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

create

public static SqlSearchCompiler create(SqlDialect dialect,
 ColumnResolver columns)

Creates a compiler for a dialect and column resolver.

Parameters:

dialect - The target dialect. Must not be null.

columns - Maps validated column names to quoted SQL references.

Returns:

A new compiler.

compile

public SqlFragment compile(Filter filter)

Compiles an already-resolved Filter tree into a boolean WHERE predicate.

Renders the full cross-column Filter.And/Filter.Or/Filter.Not tree, so a top-level $or across different columns (for example DataTables' global search) compiles correctly. Filter.And/Filter.Or with no items render as always-true/always-false (1=1/1=0) per their own contract — see SqlBeanQueryContext.appendWhere, which special-cases an empty top-level filter so an unfiltered query's WHERE clause does not pick up a spurious (1=1).

Example:

SqlFragment where = SqlSearchCompiler.create(dialect, columns) .compile(filter);

Parameters:

filter - The resolved filter, or null for no predicate.

Returns:

The predicate fragment, or null if filter is null.

Throws:

BeanQuerySyntaxException - (BAD_VALUE) If a built-in leaf is not supported by the dialect.

IllegalStateException - If a custom-operator leaf cannot be rendered for the dialect.