Package com.google.cloud.spanner.connection

Class AbstractStatementParser

java.lang.Object

com.google.cloud.spanner.connection.AbstractStatementParser

Direct Known Subclasses:

PostgreSQLStatementParser, SpannerStatementParser

@InternalApi
public abstract class AbstractStatementParser
extends Object

Internal class for the Spanner Connection API.

Parses ClientSideStatements and normal SQL statements. The parser is able to recognize the type of statement, allowing the connection API to know which method on Spanner should be called. The parser does not validate the validity of statements, except for ClientSideStatements. This means that an invalid DML statement could be accepted by the AbstractStatementParser and sent to Spanner, and Spanner will then reject it with some error message.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	AbstractStatementParser.ParametersInfo	Parameter information with positional parameters translated to named parameters.
static class	AbstractStatementParser.ParsedStatement	A statement that has been parsed
static class	AbstractStatementParser.StatementType	The type of statement that has been recognized by the parser.

Method Summary

Modifier and Type	Method	Description
boolean	checkReturningClause(String sql)	Checks if the given SQL string contains a Returning clause.
protected abstract boolean	checkReturningClauseInternal(String sql)	Checks if the given SQL string contains a Returning clause.
AbstractStatementParser.ParametersInfo	convertPositionalParametersToNamedParameters(char paramChar, String sql)	Converts all positional parameters (?) in the given sql string into named parameters.
static AbstractStatementParser	getInstance(Dialect dialect)	Get an instance of AbstractStatementParser for the specified dialect.
boolean	isDdlStatement(String sql)	Checks whether the given statement is (probably) a DDL statement.
boolean	isQuery(String sql)	Checks whether the given statement is (probably) a SELECT query.
boolean	isUpdateStatement(String sql)	Checks whether the given statement is (probably) an update statement.
AbstractStatementParser.ParsedStatement	parse(Statement statement)	Parses the given statement and categorizes it as one of the possible AbstractStatementParser.StatementTypes.
String	removeCommentsAndTrim(String sql)	Removes comments from and trims the given sql statement using the dialect of this parser.
protected abstract boolean	supportsExplain()

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static AbstractStatementParser getInstance(Dialect dialect)

Get an instance of AbstractStatementParser for the specified dialect.

Parameters:

dialect -

Returns:

parse

@InternalApi
public AbstractStatementParser.ParsedStatement parse(Statement statement)

Parses the given statement and categorizes it as one of the possible AbstractStatementParser.StatementTypes. The validity of the statement is not checked, unless it is a client-side statement.

Parameters:

statement - The statement to parse.

Returns:

the parsed and categorized statement.

isDdlStatement

@InternalApi
public boolean isDdlStatement(String sql)

Checks whether the given statement is (probably) a DDL statement. The method does not check the validity of the statement, only if it is a DDL statement based on the first word in the statement.

Parameters:

sql - The statement to check (without any comments).

Returns:

true if the statement is a DDL statement (i.e. starts with 'CREATE', 'ALTER' or 'DROP').

isQuery

@InternalApi
public boolean isQuery(String sql)

Checks whether the given statement is (probably) a SELECT query. The method does not check the validity of the statement, only if it is a SELECT statement based on the first word in the statement.

Parameters:

sql - The statement to check (without any comments).

Returns:

true if the statement is a SELECT statement (i.e. starts with 'SELECT').

isUpdateStatement

@InternalApi
public boolean isUpdateStatement(String sql)

Checks whether the given statement is (probably) an update statement. The method does not check the validity of the statement, only if it is an update statement based on the first word in the statement.

Parameters:

sql - The statement to check (without any comments).

Returns:

true if the statement is a DML update statement (i.e. starts with 'INSERT', 'UPDATE' or 'DELETE').

supportsExplain

protected abstract boolean supportsExplain()

removeCommentsAndTrim

@InternalApi
public String removeCommentsAndTrim(String sql)

Removes comments from and trims the given sql statement using the dialect of this parser.

Parameters:

sql - The sql statement to remove comments from and to trim.

Returns:

the sql statement without the comments and leading and trailing spaces.

convertPositionalParametersToNamedParameters

@InternalApi
public AbstractStatementParser.ParametersInfo convertPositionalParametersToNamedParameters(char paramChar,
                                                                                           String sql)

Converts all positional parameters (?) in the given sql string into named parameters. The parameters are named @p1, @p2, etc. This method is used when converting a JDBC statement that uses positional parameters to a Cloud Spanner Statement instance that requires named parameters. The input SQL string may not contain any comments. There is an exception case if the statement starts with a GSQL comment which forces it to be interpreted as a GoogleSql statement.

Parameters:

sql - The sql string without comments that should be converted

Returns:

A AbstractStatementParser.ParametersInfo object containing a string with named parameters instead of positional parameters and the number of parameters.

Throws:

SpannerException - If the input sql string contains an unclosed string/byte literal.

checkReturningClauseInternal

@InternalApi
protected abstract boolean checkReturningClauseInternal(String sql)

Checks if the given SQL string contains a Returning clause. This method is used only in case of a DML statement.

Parameters:

sql - The sql string without comments that has to be evaluated.

Returns:

A boolean indicating whether the sql string has a Returning clause or not.

checkReturningClause

@InternalApi
public boolean checkReturningClause(String sql)

Checks if the given SQL string contains a Returning clause. This method is used only in case of a DML statement.

Parameters:

sql - The sql string without comments that has to be evaluated.

Returns:

A boolean indicating whether the sql string has a Returning clause or not.