org.apache.calcite.sql

Interface SqlWriter

All Known Implementing Classes:

SqlPrettyWriter

public interface SqlWriter

A SqlWriter is the target to construct a SQL statement from a parse tree. It deals with dialect differences; for example, Oracle quotes identifiers as "scott", while SQL Server quotes them as [scott].

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	SqlWriter.Frame A Frame is a piece of generated text which shares a common indentation level.
static interface	SqlWriter.FrameType Frame type.
static class	SqlWriter.FrameTypeEnum Enumerates the types of frame.
static class	SqlWriter.SubQueryStyle Style of formatting sub-queries.

Field Summary

Fields

Modifier and Type	Field and Description
static SqlBinaryOperator	COMMA Comma operator.

Method Summary

Modifier and Type	Method and Description
void	dynamicParam(int index) Prints a dynamic parameter (e.g.
void	endFunCall(SqlWriter.Frame frame) Ends a list which is a call to a function.
void	endList(@Nullable SqlWriter.Frame frame) Ends a list.
void	fetchOffset(@Nullable SqlNode fetch, @Nullable SqlNode offset) Prints the OFFSET/FETCH clause.
SqlDialect	getDialect() Returns the dialect of SQL.
int	getIndentation() Returns the offset for each level of indentation.
void	identifier(String name, boolean quoted) Prints an identifier, quoting as necessary.
boolean	inQuery() Returns whether we are currently in a query context (SELECT, INSERT, UNION, INTERSECT, EXCEPT, and the ORDER BY operator).
boolean	isAlwaysUseParentheses() Returns whether to enclose all expressions in parentheses, even if the operator has high enough precedence that the parentheses are not required.
boolean	isClauseStartsLine() Returns whether this writer should start each clause (e.g.
boolean	isKeywordsLowerCase() Returns whether to output all keywords (e.g.
boolean	isQuoteAllIdentifiers() Returns whether this writer should quote all identifiers, even those that do not contain mixed-case identifiers or punctuation.
boolean	isSelectListItemsOnSeparateLines() Returns whether the items in the SELECT clause should each be on a separate line.
void	keyword(String s) Prints a sequence of keywords.
SqlWriter	list(SqlWriter.FrameTypeEnum frameType, Consumer<SqlWriter> action) Writes a list.
SqlWriter	list(SqlWriter.FrameTypeEnum frameType, SqlBinaryOperator sepOp, SqlNodeList list) Writes a list separated by a binary operator (AND, OR, or COMMA).
void	literal(String s) Prints a literal, exactly as provided.
void	newlineAndIndent() Prints a new line, and indents.
void	print(int x) Prints an integer.
void	print(String s) Prints a string, preceded by whitespace if necessary.
void	reset() Resets this writer so that it can format another expression.
void	resetSettings() Resets all properties to their default values.
void	sep(String sep) Writes a list separator, unless the separator is "," and this is the first occurrence in the list.
void	sep(String sep, boolean printFirst) Writes a list separator.
void	setNeedWhitespace(boolean needWhitespace) Sets whether whitespace is needed before the next token.
SqlWriter.Frame	startFunCall(String funName) Starts a list which is a call to a function.
SqlWriter.Frame	startList(SqlWriter.FrameTypeEnum frameType) Starts a list with no opening string.
SqlWriter.Frame	startList(SqlWriter.FrameType frameType, String open, String close) Starts a list.
SqlWriter.Frame	startList(String open, String close) Starts a list.
void	topN(@Nullable SqlNode fetch, @Nullable SqlNode offset) Prints the TOP(n) clause.
SqlString	toSqlString() Returns the contents of this writer as a 'certified kocher' SQL string.

Field Detail

COMMA

static final SqlBinaryOperator COMMA

Comma operator.

Defined in SqlWriter because it is only used while converting SqlNode to SQL; see list(FrameTypeEnum, SqlBinaryOperator, SqlNodeList).

The precedence of the comma operator is low but not zero. For instance, this ensures parentheses in select x, (select * from foo order by z), y from t.

Method Detail

reset

void reset()

Resets this writer so that it can format another expression. Does not affect formatting preferences (see resetSettings()

resetSettings

void resetSettings()

Resets all properties to their default values.

getDialect

SqlDialect getDialect()

Returns the dialect of SQL.

Returns:

SQL dialect

toSqlString

SqlString toSqlString()

Returns the contents of this writer as a 'certified kocher' SQL string.

Returns:

SQL string

literal

@Pure
void literal(String s)

Prints a literal, exactly as provided. Does not attempt to indent or convert to upper or lower case. Does not add quotation marks. Adds preceding whitespace if necessary.

keyword

@Pure
void keyword(String s)

Prints a sequence of keywords. Must not start or end with space, but may contain a space. For example, keyword("SELECT"), keyword("CHARACTER SET").

print

@Pure
void print(String s)

Prints a string, preceded by whitespace if necessary.

print

@Pure
void print(int x)

Prints an integer.

Parameters:

x - Integer

identifier

void identifier(String name,
                boolean quoted)

Prints an identifier, quoting as necessary.

Parameters:

name - The identifier name

quoted - Whether this identifier was quoted in the original sql statement, this may not be the only factor to decide whether this identifier should be quoted

dynamicParam

void dynamicParam(int index)

Prints a dynamic parameter (e.g. ? for default JDBC)

fetchOffset

void fetchOffset(@Nullable SqlNode fetch,
                 @Nullable SqlNode offset)

Prints the OFFSET/FETCH clause.

topN

void topN(@Nullable SqlNode fetch,
          @Nullable SqlNode offset)

Prints the TOP(n) clause.

See Also:

fetchOffset(org.apache.calcite.sql.SqlNode, org.apache.calcite.sql.SqlNode)

newlineAndIndent

void newlineAndIndent()

Prints a new line, and indents.

isQuoteAllIdentifiers

boolean isQuoteAllIdentifiers()

Returns whether this writer should quote all identifiers, even those that do not contain mixed-case identifiers or punctuation.

Returns:

whether to quote all identifiers

isClauseStartsLine

boolean isClauseStartsLine()

Returns whether this writer should start each clause (e.g. GROUP BY) on a new line.

Returns:

whether to start each clause on a new line

isSelectListItemsOnSeparateLines

boolean isSelectListItemsOnSeparateLines()

Returns whether the items in the SELECT clause should each be on a separate line.

Returns:

whether to put each SELECT clause item on a new line

isKeywordsLowerCase

boolean isKeywordsLowerCase()

Returns whether to output all keywords (e.g. SELECT, GROUP BY) in lower case.

Returns:

whether to output SQL keywords in lower case

startFunCall

@Pure
SqlWriter.Frame startFunCall(String funName)

Starts a list which is a call to a function.

See Also:

endFunCall(Frame)

endFunCall

@Pure
void endFunCall(SqlWriter.Frame frame)

Ends a list which is a call to a function.

Parameters:

frame - Frame

See Also:

startFunCall(String)

startList

@Pure
SqlWriter.Frame startList(String open,
                                String close)

Starts a list.

startList

@Pure
SqlWriter.Frame startList(SqlWriter.FrameTypeEnum frameType)

Starts a list with no opening string.

Parameters:

frameType - Type of list. For example, a SELECT list will be governed according to SELECT-list formatting preferences.

startList

@Pure
SqlWriter.Frame startList(SqlWriter.FrameType frameType,
                                String open,
                                String close)

Starts a list.

Parameters:

frameType - Type of list. For example, a SELECT list will be governed according to SELECT-list formatting preferences.

open - String to start the list; typically "(" or the empty string.

close - String to close the list

endList

@Pure
void endList(@Nullable SqlWriter.Frame frame)

Ends a list.

Parameters:

frame - The frame which was created by startList(java.lang.String, java.lang.String).

list

@Pure
SqlWriter list(SqlWriter.FrameTypeEnum frameType,
                     Consumer<SqlWriter> action)

Writes a list.

list

@Pure
SqlWriter list(SqlWriter.FrameTypeEnum frameType,
                     SqlBinaryOperator sepOp,
                     SqlNodeList list)

Writes a list separated by a binary operator (AND, OR, or COMMA).

sep

@Pure
void sep(String sep)

Writes a list separator, unless the separator is "," and this is the first occurrence in the list.

Parameters:

sep - List separator, typically ",".

sep

@Pure
void sep(String sep,
               boolean printFirst)

Writes a list separator.

Parameters:

sep - List separator, typically ","

printFirst - Whether to print the first occurrence of the separator

setNeedWhitespace

@Pure
void setNeedWhitespace(boolean needWhitespace)

Sets whether whitespace is needed before the next token.

getIndentation

int getIndentation()

Returns the offset for each level of indentation. Default 4.

isAlwaysUseParentheses

boolean isAlwaysUseParentheses()

Returns whether to enclose all expressions in parentheses, even if the operator has high enough precedence that the parentheses are not required.

For example, the parentheses are required in the expression (a + b) * c because the '*' operator has higher precedence than the '+' operator, and so without the parentheses, the expression would be equivalent to a + (b * c). The fully-parenthesized expression, ((a + b) * c) is unambiguous even if you don't know the precedence of every operator.

inQuery

boolean inQuery()

Returns whether we are currently in a query context (SELECT, INSERT, UNION, INTERSECT, EXCEPT, and the ORDER BY operator).