database::query::value_formatter Class Reference

Formats database values for different backends. More...

#include <value_formatter.h>

Collaboration diagram for database::query::value_formatter:

Public Member Functions
	value_formatter (database_types db_type)
	Construct formatter for specific database type.
std::string	format (const core::database_value &value) const
	Format a database value.
std::string	escape_string (const std::string &str) const
	Escape a string value.
std::string	escape_identifier (const std::string &identifier) const
	Quote and escape an identifier (table/column name)
std::string	null_literal () const
	Get NULL literal for this database.
std::string	bool_literal (bool val) const
	Get boolean literal.

Private Member Functions
std::string	format_string (const std::string &str) const
std::string	format_int (int64_t num) const
std::string	format_double (double num) const
std::string	format_bool (bool val) const
std::string	format_blob (const std::vector< uint8_t > &data) const
std::string	escape_postgresql_string (const std::string &str) const
std::string	escape_sqlite_string (const std::string &str) const

Private Attributes
database_types	db_type_

Detailed Description

Formats database values for different backends.

Responsibilities:

• Format different data types (string, int, double, bool, blob, null)
• Database-specific escaping (PostgreSQL, SQLite)
• Identifier quoting
• NULL literal formatting

Single Responsibility Principle:

• This class only handles value formatting and escaping
• Does not handle query building or condition logic

Thread Safety:

• Thread-safe after construction (immutable state)
• Can be shared across threads

Definition at line 32 of file value_formatter.h.

Constructor & Destructor Documentation

value_formatter()

database::query::value_formatter::value_formatter ( database_types db_type )

explicit

Construct formatter for specific database type.

Parameters

db_type

Target database type

Definition at line 13 of file value_formatter.cpp.

    : db_type_(db_type) {}

Member Function Documentation

bool_literal()

std::string database::query::value_formatter::bool_literal

(

bool

val

)

const

Get boolean literal.

Parameters

val	Boolean value

Returns

Database-specific boolean representation

Definition at line 80 of file value_formatter.cpp.

                                                      {
    switch (db_type_) {
        case database_types::postgres:
        case database_types::sqlite:
            return val ? "TRUE" : "FALSE";
        case database_types::mongodb:
            return val ? "true" : "false";
        case database_types::redis:
            return val ? "1" : "0";
        default:
            return val ? "1" : "0";
    }
}

References db_type_, database::mongodb, database::postgres, database::redis, and database::sqlite.

Referenced by format_bool(), and TEST_F().

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escape_identifier()

std::string database::query::value_formatter::escape_identifier

(

const std::string &

identifier

)

const

Quote and escape an identifier (table/column name)

Parameters

identifier

Identifier to escape

Returns

Quoted and escaped identifier

Definition at line 62 of file value_formatter.cpp.

                                                                              {
    switch (db_type_) {
        case database_types::postgres:
            return "\"" + identifier + "\"";
        case database_types::sqlite:
            return "\"" + identifier + "\"";
        case database_types::mongodb:
        case database_types::redis:
            return identifier;  // NoSQL doesn't quote identifiers
        default:
            return "\"" + identifier + "\"";
    }
}

References db_type_, database::mongodb, database::postgres, database::redis, and database::sqlite.

Referenced by database::query::join_builder::build(), database::query::condition_builder::format_condition(), and TEST_F().

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escape_postgresql_string()

std::string database::query::value_formatter::escape_postgresql_string ( const std::string & str ) const

private

Definition at line 154 of file value_formatter.cpp.

                                                                              {
    std::string result;
    result.reserve(str.length() + 10);
 
    for (char c : str) {
        switch (c) {
            case '\'':
                result += "''";  // PostgreSQL escapes single quotes by doubling
                break;
            case '\\':
                result += "\\\\";  // Escape backslashes
                break;
            case '\0':
                result += "\\0";  // NULL byte
                break;
            case '\n':
                result += "\\n";  // Newline
                break;
            case '\r':
                result += "\\r";  // Carriage return
                break;
            case '\t':
                result += "\\t";  // Tab
                break;
            default:
                result += c;
        }
    }
 
    return result;
}

Referenced by escape_string().

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escape_sqlite_string()

std::string database::query::value_formatter::escape_sqlite_string ( const std::string & str ) const

private

Definition at line 186 of file value_formatter.cpp.

                                                                          {
    std::string result;
    result.reserve(str.length() + 10);
 
    for (char c : str) {
        if (c == '\'') {
            result += "''";  // SQLite escapes single quotes by doubling
        } else {
            result += c;
        }
    }
 
    return result;
}

Referenced by escape_string().

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escape_string()

std::string database::query::value_formatter::escape_string

(

const std::string &

str

)

const

Escape a string value.

Parameters

str	String to escape

Returns

Escaped string (without quotes)

Definition at line 47 of file value_formatter.cpp.

                                                                   {
    switch (db_type_) {
        case database_types::postgres:
            return escape_postgresql_string(str);
        case database_types::sqlite:
            return escape_sqlite_string(str);
        case database_types::mongodb:
        case database_types::redis:
            // NoSQL databases handle escaping differently
            return str;
        default:
            return escape_sqlite_string(str);  // Safe default
    }
}

References db_type_, escape_postgresql_string(), escape_sqlite_string(), database::mongodb, database::postgres, database::redis, and database::sqlite.

Referenced by format_string(), TEST_F(), and TEST_F().

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format()

std::string database::query::value_formatter::format

(

const core::database_value &

value

)

const

Format a database value.

Parameters

value

Value to format

Returns

Formatted string representation

Definition at line 16 of file value_formatter.cpp.

                                                                       {
    return std::visit([this](auto&& arg) -> std::string {
        using T = std::decay_t<decltype(arg)>;
 
        if constexpr (std::is_same_v<T, std::monostate>) {
            return null_literal();
        }
        else if constexpr (std::is_same_v<T, std::string>) {
            return format_string(arg);
        }
        else if constexpr (std::is_same_v<T, int>) {
            return format_int(arg);
        }
        else if constexpr (std::is_same_v<T, int64_t>) {
            return format_int(arg);
        }
        else if constexpr (std::is_same_v<T, double>) {
            return format_double(arg);
        }
        else if constexpr (std::is_same_v<T, bool>) {
            return format_bool(arg);
        }
        else if constexpr (std::is_same_v<T, std::vector<uint8_t>>) {
            return format_blob(arg);
        }
        else {
            return null_literal();
        }
    }, value);
}

References format_blob(), format_bool(), format_double(), format_int(), format_string(), and null_literal().

Referenced by database::query::condition_builder::format_condition(), TEST_F(), TEST_F(), TEST_F(), and TEST_F().

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format_blob()

std::string database::query::value_formatter::format_blob ( const std::vector< uint8_t > & data ) const

private

Definition at line 123 of file value_formatter.cpp.

                                                                           {
    switch (db_type_) {
        case database_types::postgres: {
            // PostgreSQL hex format: '\x...'
            std::ostringstream oss;
            oss << "'\\x";
            for (uint8_t byte : data) {
                oss << std::hex << std::setw(2) << std::setfill('0')
                    << static_cast<int>(byte);
            }
            oss << "'";
            return oss.str();
        }
        case database_types::sqlite: {
            // SQLite hex format: X'...'
            std::ostringstream oss;
            oss << "X'";
            for (uint8_t byte : data) {
                oss << std::hex << std::setw(2) << std::setfill('0')
                    << static_cast<int>(byte);
            }
            oss << "'";
            return oss.str();
        }
        default:
            return "NULL";  // Unsupported for this database
    }
}

References db_type_, database::postgres, and database::sqlite.

Referenced by format().

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format_bool()

std::string database::query::value_formatter::format_bool ( bool val ) const

private

Definition at line 119 of file value_formatter.cpp.

                                                     {
    return bool_literal(val);
}

References bool_literal().

Referenced by format().

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format_double()

std::string database::query::value_formatter::format_double ( double num ) const

private

Definition at line 104 of file value_formatter.cpp.

                                                         {
    // Handle special values
    if (std::isnan(num)) {
        return "'NaN'";
    }
    if (std::isinf(num)) {
        return num > 0 ? "'Infinity'" : "'-Infinity'";
    }
 
    // Format with appropriate precision
    std::ostringstream oss;
    oss << std::setprecision(15) << num;
    return oss.str();
}

Referenced by format().

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format_int()

std::string database::query::value_formatter::format_int ( int64_t num ) const

private

Definition at line 100 of file value_formatter.cpp.

                                                       {
    return std::to_string(num);
}

Referenced by format().

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format_string()

std::string database::query::value_formatter::format_string ( const std::string & str ) const

private

Definition at line 96 of file value_formatter.cpp.

                                                                   {
    return "'" + escape_string(str) + "'";
}

References escape_string().

Referenced by format().

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null_literal()

std::string database::query::value_formatter::null_literal

(

)

const

Get NULL literal for this database.

Returns

"NULL" for most databases

Definition at line 76 of file value_formatter.cpp.

                                              {
    return "NULL";
}

Referenced by format(), and TEST_F().

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Member Data Documentation

db_type_

database_types database::query::value_formatter::db_type_

private

Definition at line 75 of file value_formatter.h.

Referenced by bool_literal(), escape_identifier(), escape_string(), and format_blob().

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

• database/query_builder/value_formatter.h
• database/query_builder/value_formatter.cpp