database::query::postgresql_dialect Class Reference

PostgreSQL-specific SQL dialect. More...

#include <sql_dialect.h>

Inheritance diagram for database::query::postgresql_dialect:

Collaboration diagram for database::query::postgresql_dialect:

Public Member Functions
std::string	placeholder (int index) const override
	Generate parameter placeholder.
std::string	quote_identifier (std::string_view name) const override
	Quote an identifier (table or column name)
std::string	escape_string (std::string_view str) const override
	Escape a string value for safe SQL inclusion.
std::string	returning_clause (std::string_view column="") const override
	Generate RETURNING clause for INSERT/UPDATE.
std::string	upsert_clause (const std::vector< std::string > &conflict_columns, const std::vector< std::string > &update_columns) const override
	Generate UPSERT (INSERT OR UPDATE) clause.
std::string	limit_clause (size_t limit, size_t offset) const override
	Generate LIMIT clause.
std::string	auto_increment () const override
	Get auto-increment column definition.
std::string	current_timestamp () const override
	Get current timestamp function.
std::string	concat_operator () const override
	Get string concatenation operator.
bool	supports_feature (const std::string &feature) const override
	Check if database supports specific feature.
Public Member Functions inherited from database::query::sql_dialect
virtual	~sql_dialect ()=default

Additional Inherited Members
Static Public Member Functions inherited from database::query::sql_dialect
static std::unique_ptr< sql_dialect >	create (database_types type)
	Factory method to create appropriate dialect.

Detailed Description

PostgreSQL-specific SQL dialect.

Definition at line 155 of file sql_dialect.h.

Member Function Documentation

auto_increment()

std::string database::query::postgresql_dialect::auto_increment ( ) const

overridevirtual

Get auto-increment column definition.

Returns

SQL fragment for auto-increment column

Examples:

• PostgreSQL: "SERIAL"
• SQLite: "AUTOINCREMENT"

Implements database::query::sql_dialect.

Definition at line 101 of file sql_dialect.cpp.

                                                   {
    return "SERIAL";
}

concat_operator()

std::string database::query::postgresql_dialect::concat_operator ( ) const

overridevirtual

Get string concatenation operator.

Returns

Operator or function for concatenation

Examples:

• PostgreSQL: "||"
• SQLite: "||"

Implements database::query::sql_dialect.

Definition at line 109 of file sql_dialect.cpp.

                                                    {
    return "||";
}

current_timestamp()

std::string database::query::postgresql_dialect::current_timestamp ( ) const

overridevirtual

Get current timestamp function.

Returns

SQL function for current timestamp

Examples:

• PostgreSQL: "CURRENT_TIMESTAMP"
• SQLite: "CURRENT_TIMESTAMP"

Implements database::query::sql_dialect.

Definition at line 105 of file sql_dialect.cpp.

                                                      {
    return "CURRENT_TIMESTAMP";
}

escape_string()

std::string database::query::postgresql_dialect::escape_string ( std::string_view str ) const

overridevirtual

Escape a string value for safe SQL inclusion.

Parameters

str	The string to escape

Returns

Escaped string (without surrounding quotes)

Implements database::query::sql_dialect.

Definition at line 43 of file sql_dialect.cpp.

                                                                    {
    std::string result;
    result.reserve(str.size());
    for (char c : str) {
        if (c == '\'') {
            result += "''";  // Escape single quotes by doubling
        } else if (c == '\\') {
            result += "\\\\";  // Escape backslashes
        } else {
            result += c;
        }
    }
    return result;
}

limit_clause()

std::string database::query::postgresql_dialect::limit_clause ( size_t limit, size_t offset ) const

overridevirtual

Generate LIMIT clause.

Parameters

limit	Maximum number of rows
offset	Number of rows to skip

Returns

Database-specific LIMIT clause

Examples:

• PostgreSQL: "LIMIT 10 OFFSET 5"
• SQLite: "LIMIT 10 OFFSET 5"

Implements database::query::sql_dialect.

Definition at line 93 of file sql_dialect.cpp.

                                                                            {
    std::string clause = "LIMIT " + std::to_string(limit);
    if (offset > 0) {
        clause += " OFFSET " + std::to_string(offset);
    }
    return clause;
}

placeholder()

std::string database::query::postgresql_dialect::placeholder ( int index ) const

overridevirtual

Generate parameter placeholder.

Parameters

index

1-based parameter index

Returns

Database-specific placeholder string

Examples:

• PostgreSQL: "$1", "$2", "$3"
• SQLite: "?1", "?2", "?3"

Implements database::query::sql_dialect.

Definition at line 24 of file sql_dialect.cpp.

                                                         {
    return "$" + std::to_string(index);
}

quote_identifier()

std::string database::query::postgresql_dialect::quote_identifier ( std::string_view name ) const

overridevirtual

Quote an identifier (table or column name)

Parameters

name	The identifier to quote

Returns

Quoted identifier

Examples:

• PostgreSQL: "\"column_name\""
• SQLite: "\"column_name\""

Implements database::query::sql_dialect.

Definition at line 28 of file sql_dialect.cpp.

                                                                        {
    std::string result;
    result.reserve(name.size() + 2);
    result += '"';
    for (char c : name) {
        if (c == '"') {
            result += "\"\"";  // Escape double quotes by doubling
        } else {
            result += c;
        }
    }
    result += '"';
    return result;
}

Referenced by returning_clause(), and upsert_clause().

Here is the caller graph for this function:

returning_clause()

std::string database::query::postgresql_dialect::returning_clause ( std::string_view column = "" ) const

overridevirtual

Generate RETURNING clause for INSERT/UPDATE.

Parameters

column

The column to return (empty for all)

Returns

Database-specific RETURNING clause or empty if unsupported

Examples:

• PostgreSQL: " RETURNING id"
• SQLite: " RETURNING id" (3.35+)

Implements database::query::sql_dialect.

Definition at line 58 of file sql_dialect.cpp.

                                                                          {
    if (column.empty()) {
        return " RETURNING *";
    }
    return " RETURNING " + quote_identifier(column);
}

References quote_identifier().

Here is the call graph for this function:

supports_feature()

bool database::query::postgresql_dialect::supports_feature ( const std::string & feature ) const

overridevirtual

Check if database supports specific feature.

Parameters

feature

Feature name

Returns

true if supported

Implements database::query::sql_dialect.

Definition at line 113 of file sql_dialect.cpp.

                                                                        {
    // PostgreSQL supports most SQL features
    if (feature == "window_functions") return true;
    if (feature == "cte") return true;  // Common Table Expressions
    if (feature == "recursive_cte") return true;
    if (feature == "json") return true;
    if (feature == "full_outer_join") return true;
    if (feature == "returning") return true;  // RETURNING clause
    if (feature == "array") return true;
    if (feature == "upsert") return true;  // ON CONFLICT
    return false;
}

upsert_clause()

std::string database::query::postgresql_dialect::upsert_clause ( const std::vector< std::string > & conflict_columns, const std::vector< std::string > & update_columns ) const

overridevirtual

Generate UPSERT (INSERT OR UPDATE) clause.

Parameters

conflict_columns	Columns that define conflict
update_columns	Columns to update on conflict

Returns

Database-specific upsert clause

Examples:

• PostgreSQL: "ON CONFLICT (id) DO UPDATE SET ..."
• SQLite: "ON CONFLICT (id) DO UPDATE SET ..."

Implements database::query::sql_dialect.

Definition at line 65 of file sql_dialect.cpp.

                                                      {
 
    if (conflict_columns.empty()) {
        return "";
    }
 
    std::string result = "ON CONFLICT (";
    for (size_t i = 0; i < conflict_columns.size(); ++i) {
        if (i > 0) result += ", ";
        result += quote_identifier(conflict_columns[i]);
    }
    result += ")";
 
    if (update_columns.empty()) {
        result += " DO NOTHING";
    } else {
        result += " DO UPDATE SET ";
        for (size_t i = 0; i < update_columns.size(); ++i) {
            if (i > 0) result += ", ";
            std::string quoted = quote_identifier(update_columns[i]);
            result += quoted + " = EXCLUDED." + quoted;
        }
    }
    return result;
}

References quote_identifier().

Here is the call graph for this function:

---

The documentation for this class was generated from the following files:

• database/query_builder/sql_dialect.h
• database/query_builder/sql_dialect.cpp