/*
 * Copyright 2002-2019 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.jdbc.core.namedparam;

import org.springframework.jdbc.support.JdbcUtils;
import org.springframework.lang.Nullable;

Interface that defines common functionality for objects that can offer parameter values for named SQL parameters, serving as argument for NamedParameterJdbcTemplate operations. 
This interface allows for the specification of SQL type in addition
to parameter values. All parameter values and types are identified by
specifying the name of the parameter.
Intended to wrap various implementations like a Map or a JavaBean
with a consistent interface.
Author:
Thomas Risberg, Juergen Hoeller
See Also:
NamedParameterJdbcOperations
NamedParameterJdbcTemplate
MapSqlParameterSource
BeanPropertySqlParameterSource
Since:
2.0/**
 * Interface that defines common functionality for objects that can
 * offer parameter values for named SQL parameters, serving as argument
 * for {@link NamedParameterJdbcTemplate} operations.
 *
 * <p>This interface allows for the specification of SQL type in addition
 * to parameter values. All parameter values and types are identified by
 * specifying the name of the parameter.
 *
 * <p>Intended to wrap various implementations like a Map or a JavaBean
 * with a consistent interface.
 *
 * @author Thomas Risberg
 * @author Juergen Hoeller
 * @since 2.0
 * @see NamedParameterJdbcOperations
 * @see NamedParameterJdbcTemplate
 * @see MapSqlParameterSource
 * @see BeanPropertySqlParameterSource
 */
public interface SqlParameterSource {

	
Constant that indicates an unknown (or unspecified) SQL type. To be returned from getType when no specific SQL type known. 
See Also:
getSqlType
Types/**
	 * Constant that indicates an unknown (or unspecified) SQL type.
	 * To be returned from {@code getType} when no specific SQL type known.
	 * @see #getSqlType
	 * @see java.sql.Types
	 */
	int TYPE_UNKNOWN = JdbcUtils.TYPE_UNKNOWN;


	
Determine whether there is a value for the specified named parameter.
Params:
paramName – the name of the parameter
Returns:
whether there is a value defined/**
	 * Determine whether there is a value for the specified named parameter.
	 * @param paramName the name of the parameter
	 * @return whether there is a value defined
	 */
	boolean hasValue(String paramName);

	
Return the parameter value for the requested named parameter.
Params:
paramName – the name of the parameter
Throws:
IllegalArgumentException – if there is no value for the requested parameter
Returns:
the value of the specified parameter/**
	 * Return the parameter value for the requested named parameter.
	 * @param paramName the name of the parameter
	 * @return the value of the specified parameter
	 * @throws IllegalArgumentException if there is no value for the requested parameter
	 */
	@Nullable
	Object getValue(String paramName) throws IllegalArgumentException;

	
Determine the SQL type for the specified named parameter.
Params:
paramName – the name of the parameter
See Also:
TYPE_UNKNOWN
Returns:
the SQL type of the specified parameter, or TYPE_UNKNOWN if not known/**
	 * Determine the SQL type for the specified named parameter.
	 * @param paramName the name of the parameter
	 * @return the SQL type of the specified parameter,
	 * or {@code TYPE_UNKNOWN} if not known
	 * @see #TYPE_UNKNOWN
	 */
	default int getSqlType(String paramName) {
		return TYPE_UNKNOWN;
	}

	
Determine the type name for the specified named parameter.
Params:
paramName – the name of the parameter
Returns:
the type name of the specified parameter, or null if not known/**
	 * Determine the type name for the specified named parameter.
	 * @param paramName the name of the parameter
	 * @return the type name of the specified parameter,
	 * or {@code null} if not known
	 */
	@Nullable
	default String getTypeName(String paramName) {
		return null;
	}

	
Enumerate all available parameter names if possible.
This is an optional operation, primarily for use with SimpleJdbcInsert and SimpleJdbcCall. 
See Also:
SqlParameterSourceUtils.extractCaseInsensitiveParameterNames
Returns:
the array of parameter names, or null if not determinable
Since:
5.0.3/**
	 * Enumerate all available parameter names if possible.
	 * <p>This is an optional operation, primarily for use with
	 * {@link org.springframework.jdbc.core.simple.SimpleJdbcInsert}
	 * and {@link org.springframework.jdbc.core.simple.SimpleJdbcCall}.
	 * @return the array of parameter names, or {@code null} if not determinable
	 * @since 5.0.3
	 * @see SqlParameterSourceUtils#extractCaseInsensitiveParameterNames
	 */
	@Nullable
	default String[] getParameterNames() {
		return null;
	}

}